Quantitative trait loci （QTLs） for plant height in wheat （Triticum aestivum L.） were studied using a set of 168 doubled haploid （DH） lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage ...Quantitative trait loci （QTLs） for plant height in wheat （Triticum aestivum L.） were studied using a set of 168 doubled haploid （DH） lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai＇an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTL×environment interactions （QEs）. Two major QTLs, Qph4B and Qph4D, which accounted for 14.51% and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rhtl and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL effects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection （MAS）.展开更多
AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: Th...AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: The seventeen patients (7 male and 10 female; mean age 67.8 years) with difficult common bile duct (CBD) stones were not amenable for conventional endoscopic maneuvers such as sphincterotomy and mechanical lithotripsy were included in this study. Laser wavelengths of 532 nm and 1064 nm as a double pulse were applied with pulse energy of 120 mJ. The laser fiber was advanced under fluoroscopic control through the ERCP balloon catheter. Laser lithotripsy was continued until the fragment size seemed to be less than 10 mm. Endoscopic extraction of the stones and fragments was performed with the use of the Dormia basket and balloon catheter. RESULTS: Bile duct clearance was achieved in 15 of 17 patients (88%). The mean number of treatment sessions was 1.7 ± 0.6. Endoscopic stone removal could not be achieved in 2 patients (7%). Adverse effects were noted in three patients (hemobilia, pancreatitis, and cholangitis). CONCLUSION: The Frequency Doubled Double Pulse Nd:YAG (FREDDY) laser may be an effective and safe technique in treatment of difficult bile duct stones.展开更多
A new doubled haploid (DH) rice population was established from a cross between WBPH-resistant japonica Chunjiang 06 (CJ-06) and susceptible indica TN1. Sucking inhibitory and ovicidal resistance of the DH rice lines ...A new doubled haploid (DH) rice population was established from a cross between WBPH-resistant japonica Chunjiang 06 (CJ-06) and susceptible indica TN1. Sucking inhibitory and ovicidal resistance of the DH rice lines were evaluated on the basis of non-preference response of WBPH immigrants and honeydew excretion by WBPH females, and appearance of watery lesions in the necrotic discoloration of leaf sheaths ovipositied by WBPH,respectively. Both the major gene resistance to WBPH, sucking inhibitory and ovicidal resistance, showed 1 (resistant): 1 (susceptible) segregation ratio in the DH population. Relative density of WBPH populations and damage scores in the DH population indicated combined functions of both the major resistance genes as well as QTLs affecting the host plant response to WBPH infestations. Thus, the newly developed CJ-06/TN1 DH population could be a useful material to analyze major genes and QTLs for WBPH resistance in japonica rice.展开更多
Whitebacked planthopper (WBPH) -resistance in a japonica / indica doubled haploid (DH) rice population established from a cross between WBPH-resistant japonica Chun]iang 06 and susceptible indica TN1, was comparativel...Whitebacked planthopper (WBPH) -resistance in a japonica / indica doubled haploid (DH) rice population established from a cross between WBPH-resistant japonica Chun]iang 06 and susceptible indica TN1, was comparatively evaluated through a field experiment based on the WBPH immigrant density and standardized seedbox screening test (SSST). All the susceptible DH lines in the field experiment behaved accordingly in SSST. However, 35 of resistant 66 lines (53%) in the field, were categorized to susceptible groups in SSST. Likewise, there were no significant differences in WBPH immigrant densities among 70 DH lines that were highly resistant to susceptible in SSST. The results revealed that SSST could not evaluate properly WBPH resistance in the DH lines. Four QTLs for WBPH-resistance phenotyped by the immigrant density were detected on chromosomes 2, 3, 4, and 11. Of them, the QTL on chromosome 4 was the most effective (LOD 21.8, variance 78%). Five QTLs associated with seedling mortality were mapped on chromosomes 2, 3, 4, 5 and 6. In addition to the QTL (LOD 10.5, variance 68%) on chromosome 4, there was another major QTL (LOD 12.7, variance 71%) located on chromosome 5, which was SSST-specific but might be irrespective of the WBPH resistance traits.展开更多
ABSTRACT Rainfall responses to doubled atmospheric carbon dioxide concentration were investigated through the analysis of two pairs of two-dimensional cloud-resolving model sensitivity experiments. One pair of experi...ABSTRACT Rainfall responses to doubled atmospheric carbon dioxide concentration were investigated through the analysis of two pairs of two-dimensional cloud-resolving model sensitivity experiments. One pair of experiments simulated pre-summer heavy rainfall over southern China around the summer solstice, whereas the other pair of experiments simulated tropical rainfall around the winter solstice. The analysis of the time and model domain mean heat budget revealed that the enhanced local atmospheric warming was associated with doubled carbon dioxide through the weakened infrared radiative cooling during the summer solstice. The weakened mean pre-summer rainfall corresponded to the weakened mean infrared radiative cooling. Doubled carbon dioxide increased the mean tropical atmospheric warming via the enhanced mean latent heat in correspondence with the strengthened mean infrared radiative cooling during the winter solstice. The enhanced mean tropical rainfall was associated with the increased mean latent heat.展开更多
Simultaneous heading of plants within the same rice variety, also refer to heading synchrony, is an important factor that affects simultaneous ripening of the variety. Understanding of the genetic basis of heading syn...Simultaneous heading of plants within the same rice variety, also refer to heading synchrony, is an important factor that affects simultaneous ripening of the variety. Understanding of the genetic basis of heading synchrony may contribute to molecular breeding of rice with simultaneous heading and ripening. In the present study, a doubled haploid （DH） population, derived from a cross between Chunjiang 06 and TN1 was used to analyze quantitative trait locus （QTL） for heading synchrony related traits, i.e., early heading date （EHD）, late heading date （LHD）, heading asynchrony （HAS）, and tiller number （PN）. A total of 19 QTLs for four traits distributed on nine chromosomes were detected in two environments. One QTL, qHAS-8 for HAS, explained 27.7% of the phenotypic variation, co-located with the QTLs for EHD and LHD, but it was only significant under long-day conditions in Hangzhou, China. The other three QTLs, qHAS-6, qHAS-9, and qHAS-10, were identified under short-day conditions in Hainan, China, each of which explained about 11% of the phenotypic variation. Two of them, qHAS-6 and qHAS-9, were co-located with the QTLs for EHD and LHD. Two QTLs, qPN-4 and qPN-5 for PN, were detected in Hangzhou, and qPN-5 was also detected in Hainan. However, none of them was co-located with QTLs for EHD, LHD, and HAS, suggesting that PN and HAS were controlled by different genetic factors. The results of this study can be useful in marker assisted breeding for improvement of heading synchrony.展开更多
In order to understand the genetic basis for Zeleny sedimentation value （ZSV） of wheat, a doubled haploid （DH） population Huapei 3 × Yumai 57 （Yumai 57 is superior to Huapei 3 for ZSV）, and a linkage map co...In order to understand the genetic basis for Zeleny sedimentation value （ZSV） of wheat, a doubled haploid （DH） population Huapei 3 × Yumai 57 （Yumai 57 is superior to Huapei 3 for ZSV）, and a linkage map consisting of 323 marker loci were used to search QTLs for ZSV. This program was based on mixed linear models and allowed simultaneous mapping of additive effect QTLs, epistatic QTLs, and QTL x environment interactions （QEs）. The DH population and the parents were evaluated for ZSV in three field trials. Mapping analysis produced a total of 8 QTLs and 2 QEs for ZSV with a single QTL explaining 0.64-14.39% of phenotypic variations. Four additive QTLs, 4 pairs of epistatic QTLs, and two QEs collectively explained 46.11% of the phenotypic variation （PVE）. This study provided a precise location of ZSV gene within the Xwmc 93 and GluD1 interval, which was designated as Qzsv-1D. The information obtained in this study should be useful for manipulating the QTLs for ZSV by marker assisted selection （MAS） in wheat breeding programs.展开更多
Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants ...Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants is onerous,and limited biological or breeding work has been carried out on DH individuals or populations.In this study,we provide an effective protocol for poplar haploid induction based on an anther culture method.A total of 96 whole DH plant lines were obtained using an F1hybrid of Populus simonii×P.nigra as a donor tree.The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree.Each DH line displayed distinct features compared to those of the other DH lines or the donor tree.Additionally,some excellent homozygous lines have the potential to be model plants in genetic and breeding studies.展开更多
QTLs for drought tolerance at the rice seedling stage were analyzed using a doubled haploid （DH） population consisted of 251 lines from the cross between a japonica parent Maybelle and an indica parent Baiyeqiu. A g...QTLs for drought tolerance at the rice seedling stage were analyzed using a doubled haploid （DH） population consisted of 251 lines from the cross between a japonica parent Maybelle and an indica parent Baiyeqiu. A genetic linkage map with 226 SSR marker loci was constructed. Single-locus analysis following composite interval mapping （CIM） detected a total of five QTLs located on five different chromosomes of rice. Four QTLs were also detected following two-locus analysis, resolving two pairs of epistatic QTLs （E-QTI_s） with positive and additive genetic effects. The results indicated that the alleles from the parent Baiyeqiu contributed DH population to improve drought tolerance at the seedling stage.展开更多
Despite significant yield advantage over inbred rice, the adoption rate of hybrid rice in India is very low due to the high seed cost and poor quality of the produce. To alleviate the problem, we initiated a doubled h...Despite significant yield advantage over inbred rice, the adoption rate of hybrid rice in India is very low due to the high seed cost and poor quality of the produce. To alleviate the problem, we initiated a doubled haploid （DH） breeding approach to develop new lines from two elite indica rice hybrids （CRHR5 and CRHR7） through rapid fixation of homozygosity in the recombinants. In vitro culture of the rice anthers resulted in 243 and 186 fertile DH lines of CRHR5 and CRHR7, respectively. Flow cytometric and pollen fertility analyses confirmed the DH ploidy status of the regenerations. Morpho-agronomic evaluation revealed 100% uniformity and stability for all the characters in the DH lines of both hybrids. Nineteen promising DH lines of each hybrid were advanced to A2 generation for yield evaluation. The yield levels of the DH lines ranged from 5 097-6 965 kg/hm^2 for CRHR5 and 5 141-7 235 kg/hm^2 for CRHR7, which were at par or higher than the parental hybrids. Physico-chemical characterization and cooking quality analyses revealed significant and acceptable values for grain length and width, alkali spreading value, amylose content and water uptake ratio of the selected DH lines. Three DH lines, CR5-10, CR5-49, CR5-61 from CRHR5, and four DH lines, CR7-5, CR7-7, CR7-12 and CR7-52 from CRHR7, showed significant grain yield and quality characteristics and have been recommended for multi-location trials for subsequent release as new indica doubled haploid rice varieties.展开更多
Sheath blight（SB） disease,caused by Rhizoctonia solani Kuhn,is one of the most serious diseases causing rice（Oryza sativa L.） yield loss worldwide.A doubled haploid（DH） population was constructed from a cross be...Sheath blight（SB） disease,caused by Rhizoctonia solani Kuhn,is one of the most serious diseases causing rice（Oryza sativa L.） yield loss worldwide.A doubled haploid（DH） population was constructed from a cross between a japonica variety CJ06 and an indica variety TN1,and to analyze the quantitative trait loci（QTLs） for SB resistance under three different environments（environments 1-3）.Two traits were recorded to evaluate the SB resistance,namely lesion height（LH） and disease rating（DR）.Based on field evaluation of SB resistance and a genetic map constructed with 214 markers,a total of eight QTLs were identified for LH and eight QTLs for DR under three environments,respectively.The QTLs for LH were anchored on chromosomes 1,3,4,5,6,and 8,and explained 4.35-17.53%of the phenotypic variation.The SB resistance allele of qHNLH4 from TN1 decreased LH by 3.08 cm,and contributed to 17.53%of the variation at environment 1.The QTL for LH（qHZaLH8） detected on chromosome 8 in environment 2 explained 16.71%of the variation,and the resistance allele from CJ06 reduced LH by 4.4 cm.Eight QTLs for DR were identified on chromosomes 1,5,6,8,9,11,and 12 under three conditions with the explained variation from 2.0 to 11.27%.The QTL for DR（qHZaDR8）,which explained variation of 11.27%,was located in the same interval as that of qHZaLH8,both QTLs were detected in environment 2.A total of six pairs of digenic epistatic loci for DR were detected in three conditions,but no epistatic locus was observed for LH.In addition,we detected 12 QTLs for plant height（PH） in three environments.None of the PH-QTLs were co-located with the SB-QTLs.The results facilitate our understanding of the genetic basis for SB resistance in rice.展开更多
This study determined the indirect selection index of doubled haploid(DH)rice using a multivariate analysis approach to select lines adaptive to salinity stress,comprising three experiments.The first experiment involv...This study determined the indirect selection index of doubled haploid(DH)rice using a multivariate analysis approach to select lines adaptive to salinity stress,comprising three experiments.The first experiment involved the selection of good agronomic characters in a field experiment conducted at an experimental station in Bogor,Indonesia.The second experiment involved salinity tolerance screening through hydroponic cultures using 0 and 120 mmol/L NaCl,conducted at a greenhouse in Bogor.The third experiment involved the validation of the indirect adaptability selection index(IASI)through a field experiment in Sukra(saline area).Field experiments followed a randomized complete block design(RCBD),whereas an RCBD nested factorial design was used for the greenhouse experiment.The first and second experiments used 56 DH lines and four check varieties with three replications.In the second experiment,Pokkali and IR29 varieties were also added as tolerant and sensitive checks of salinity,respectively.The third experiment used 28 selected DH lines,Inpari 29 and one sensitive DH line.The good agronomic index(GAI)was 0.465 yield+0.433 number of productive tillers+0.31 number of filled grains.This generated 24 DH rice lines with good agronomic traits.The salinity tolerance index(SaTI)was developed through the average of standardized salinity tolerance score and salinity selection index based on discriminant analysis.This generated 34 DH rice lines with good salinity stress tolerance.The IASI(IASI=GAI–SaTI)selected 28 DH rice lines adaptive to salinity stress and it was considered effective by Sukra validation.展开更多
Field performance of whitebacked planthopper （WBPH）-resistance of four phenotypes was evaluated in Chunjiang 06 （C J-06） / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory an...Field performance of whitebacked planthopper （WBPH）-resistance of four phenotypes was evaluated in Chunjiang 06 （C J-06） / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory and ovicidal traits inherited independently from C J-06. WBPH established the highest populations in susceptible DH lines that had neither sucking inhibitorynor ovicidal resistance. Both immigration and subsequent population levels were kept below the damage-causing density in the sucking inhibitory DH lines even under a WBPH outbreak. WBPH could not build up populations in the DH lines having both the sucking inhibitory and ovicidal resistance. Although WBPH immigrated preferentially to non-sucking inhibitory DH lines with ovicidal resistance, subsequent population buildup was significantly suppressed. It was concluded that the differential performance to WBPH-resistance in CJ-06 / TN1 DH lines was primarily due to the sucking inhibitory trait, and complementarity to the ovicidal trait.展开更多
A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conve...A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conversion efficiency is to decrease the loss of fundamental wave. In the experiments, a fundamental mode output laser was acquired. When the pumping power was 12 W, 2.6 W average output power at 1 064 nm with AO Q switch was obtained. 2.1 W average output power at 532 nm was obtained with intracavity frequency doubling, and the highest second harmonic conversion efficiency was 82 0 0.展开更多
Stability analysis of grain yield is an efficient tool for the selection of varieties adapted to fairly wide cultivation zone. A study aims to determine adaptability and stability for grain yield and agronomic perform...Stability analysis of grain yield is an efficient tool for the selection of varieties adapted to fairly wide cultivation zone. A study aims to determine adaptability and stability for grain yield and agronomic performance of 10 elite Doubled Haploid (DH) rice genotypes generated through another culture technique, along with local cultivar Umgar as a check under irrigated lowland conditions in three different environments in the central clay plains of the Sudan;during two cropping seasons 2019 and 2020. The trials were conducted in a randomized complete block design with three replications. Grain yield stability was studied, using the Additive Main effect and Multiplicative Interaction (AMMI) model. Bi-plots were developed following GGE bi-plot methodology over the six environments. The combined analysis of variance revealed significant to highly significant (P < 0.001) effects of genotypes, environments, and genotype by environment interaction. Moreover, the analysis of variance based on AMMI indicated significant genotypes, environments, and GE interaction with a total variation of 43.16%, 44.26% and 12.58% respectively. A biplot-AMMI analysis and yield stability index incorporating the AMMI stability value and yield in a single non-parametric index were used to identify the genotypes with the highest and stable yield. The overall mean for grain yield was 5.69 t/ha, with a range of 5.77 to 4.12 t/ha. The genotypes k150147, k150870, k150032, k150912, and k150307 out yielded the local check Umgar by 40%, 38%, 34%, 34% and 33% respectively. The most genotypes were mid-early maturities which were harvested at 107, 113, 108, 109 and 112 days after sowing, respectively. These five genotypes also showed grain yield stability along with their high mean yield performance according to the AMMI analysis and widely adaptable to the tested locations. Therefore, the five out yielding genotypes will be considered for cultivation under irrigated system condition in central clay in the Sudan.展开更多
The development of new rice varieties is highly dependent on genetic diversity in desirable agronomic traits. Therefore, this study aimed to identify potential genotypes having the characters of Korean varieties (Tong...The development of new rice varieties is highly dependent on genetic diversity in desirable agronomic traits. Therefore, this study aimed to identify potential genotypes having the characters of Korean varieties (Tongil-type) and japonica developed through doubled haploid (DH) technology to apply in our breeding materials. 35 elite DH lines derived from another culture of Korean and African rice along with two local checks were planted in a randomized complete block design with three replications during the two seasons of 2019 and 2020. All evaluated genotypes exhibited a wide and significant variation in the ten measured traits. The highest heritability related to high genetic advance was recorded for the number of tiller/plant, grain yield t/ha, number of filled grain per panicle, and thousand grain weights (g). Genotypic coefficient of variation and genetic advance were recorded for number of tiller/plant, number of filled grain per panicle, 1000 grain weight and grain yield t/ha in both seasons. Moreover, there was a highly significant and positive correlation of grain yield with number of filled grain per panicle (0.65), number of tiller/plant (0.64) and number of panicle per m<sup>2</sup> (0.54). Cluster analysis based on grain yield components trait grouped the 37 rice genotypes into four clusters. Cluster B was the largest and consisted of 13 genotypes. Finally, it could be concluded that, based on number of productive tillers, number of filled grain/panicle, number of panicle per m<sup>2</sup>, and grain yield, the lines KF170506, KF170509, KF170542, KF170530, KF170543, KF170500 and KF170510 were high potential for further selection for new type of irrigated rice. In addition, hybridization of these 7 high-yielding could be used to achieve higher heterosis among the genotypes. Furthermore, this evaluation could be useful in developing reliable selection indices for improving rice breeding programs.展开更多
It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represent...It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represents a ran-dom array of the microspore population, i.e.whether gametic selection occurs in androgene-sis. A DH population including 132 lines de-展开更多
We report an enhancement cavity for femtosecond Ti：sapphire laser at the repetition rate of 170 MHz. An enhancement factor of 24 is obtained when the injecting pulses have an average power of 1 W and a pulse duration...We report an enhancement cavity for femtosecond Ti：sapphire laser at the repetition rate of 170 MHz. An enhancement factor of 24 is obtained when the injecting pulses have an average power of 1 W and a pulse duration of 80 fs. By placing a BBO crystal at the focus of the cavity, we obtain a 392-mW intracavity doubled-frequency laser, corresponding to a conversion efficiency of 43%. The output power has a long-term stability with a root mean square （RMS） of 0.036%.展开更多
Aiming to join the highincome club within five years The Chinese Communist Party(CCP)released its Proposals for formulating the 14th Five-Year Plan(2021-2025)and the 2035 vision on 3 November 2020.Leaders are aiming t...Aiming to join the highincome club within five years The Chinese Communist Party(CCP)released its Proposals for formulating the 14th Five-Year Plan(2021-2025)and the 2035 vision on 3 November 2020.Leaders are aiming to raise the GDP per capita to the level of a“moderately developed country”by 2035;it appears confident that doubling the GDP within 15 years to achieve this is feasible,but has stopped short of making this an official target.展开更多
Doubled haploid(DH)technology and synthetic apomixis approaches can considerably shorten breeding cycles and enhance breeding efficiency.Compared with traditional breeding methods,DH technology offers the advantage of...Doubled haploid(DH)technology and synthetic apomixis approaches can considerably shorten breeding cycles and enhance breeding efficiency.Compared with traditional breeding methods,DH technology offers the advantage of rapidly generating inbred lines,while synthetic apomixis can effectively fix hybrid vigor.In this review,we focus on(i)recent advances in identifying and characterizing genes responsible for haploid induction(Hl),(ii)the molecular mechanisms of Hl,(ili)spontaneous haploid genome doubling,and(iv)crop synthetic apomixis.We also discuss the challenges and potential solutions for future crop breeding programs utilizing DH technology and synthetic apomixis.Finally,we provide our perspectives about how to integrate DH and synthetic apomixis for precision breeding and de novo domestication.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.30471082)the Hi-Tech Research and Development(863)Program of China(No.2006AA100101 and 2006AA10Z1E9).
文摘Quantitative trait loci （QTLs） for plant height in wheat （Triticum aestivum L.） were studied using a set of 168 doubled haploid （DH） lines, which were derived from the cross Huapei 3/Yumai 57. A genetic linkage map was constructed using 283 SSR and 22 EST-SSR markers. The DH population and the parents were evaluated for wheat plant height in 2005 and 2006 in Tai＇an and 2006 in Suzhou. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. Four additive QTLs and five pairs of epistatic effects were detected, which were distributed on chromosomes 3A, 4B, 4D, 5A, 6A, 7B, and 7D. Among them, three additive QTLs and three pairs of epistatic QTLs showed QTL×environment interactions （QEs）. Two major QTLs, Qph4B and Qph4D, which accounted for 14.51% and 20.22% of the phenotypic variation, were located similar to the reported locations of the dwarfing genes Rhtl and Rht2, respectively. The Qph3A-2 with additive effect was not reported in previous linkage mapping studies. The total QTL effects detected for the plant height explained 85.04% of the phenotypic variation, with additive effects 46.07%, epistatic effects 19.89%, and QEs 19.09%. The results showed that both additive effects and epistatic effects were important genetic bases of wheat plant height, which were subjected to environmental modifications, and caused dramatic changes in phenotypic effects. The information obtained in this study will be useful for manipulating the QTLs for wheat plant height by molecular marker-assisted selection （MAS）.
基金The 2007 research fund of Wonkwang University and Wonkwang Clinical Research Institute
文摘AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: The seventeen patients (7 male and 10 female; mean age 67.8 years) with difficult common bile duct (CBD) stones were not amenable for conventional endoscopic maneuvers such as sphincterotomy and mechanical lithotripsy were included in this study. Laser wavelengths of 532 nm and 1064 nm as a double pulse were applied with pulse energy of 120 mJ. The laser fiber was advanced under fluoroscopic control through the ERCP balloon catheter. Laser lithotripsy was continued until the fragment size seemed to be less than 10 mm. Endoscopic extraction of the stones and fragments was performed with the use of the Dormia basket and balloon catheter. RESULTS: Bile duct clearance was achieved in 15 of 17 patients (88%). The mean number of treatment sessions was 1.7 ± 0.6. Endoscopic stone removal could not be achieved in 2 patients (7%). Adverse effects were noted in three patients (hemobilia, pancreatitis, and cholangitis). CONCLUSION: The Frequency Doubled Double Pulse Nd:YAG (FREDDY) laser may be an effective and safe technique in treatment of difficult bile duct stones.
文摘A new doubled haploid (DH) rice population was established from a cross between WBPH-resistant japonica Chunjiang 06 (CJ-06) and susceptible indica TN1. Sucking inhibitory and ovicidal resistance of the DH rice lines were evaluated on the basis of non-preference response of WBPH immigrants and honeydew excretion by WBPH females, and appearance of watery lesions in the necrotic discoloration of leaf sheaths ovipositied by WBPH,respectively. Both the major gene resistance to WBPH, sucking inhibitory and ovicidal resistance, showed 1 (resistant): 1 (susceptible) segregation ratio in the DH population. Relative density of WBPH populations and damage scores in the DH population indicated combined functions of both the major resistance genes as well as QTLs affecting the host plant response to WBPH infestations. Thus, the newly developed CJ-06/TN1 DH population could be a useful material to analyze major genes and QTLs for WBPH resistance in japonica rice.
文摘Whitebacked planthopper (WBPH) -resistance in a japonica / indica doubled haploid (DH) rice population established from a cross between WBPH-resistant japonica Chun]iang 06 and susceptible indica TN1, was comparatively evaluated through a field experiment based on the WBPH immigrant density and standardized seedbox screening test (SSST). All the susceptible DH lines in the field experiment behaved accordingly in SSST. However, 35 of resistant 66 lines (53%) in the field, were categorized to susceptible groups in SSST. Likewise, there were no significant differences in WBPH immigrant densities among 70 DH lines that were highly resistant to susceptible in SSST. The results revealed that SSST could not evaluate properly WBPH resistance in the DH lines. Four QTLs for WBPH-resistance phenotyped by the immigrant density were detected on chromosomes 2, 3, 4, and 11. Of them, the QTL on chromosome 4 was the most effective (LOD 21.8, variance 78%). Five QTLs associated with seedling mortality were mapped on chromosomes 2, 3, 4, 5 and 6. In addition to the QTL (LOD 10.5, variance 68%) on chromosome 4, there was another major QTL (LOD 12.7, variance 71%) located on chromosome 5, which was SSST-specific but might be irrespective of the WBPH resistance traits.
基金supported by 985 Program of Zhejiang University under Grant No.188020+193432602/215National Natural Science Foundation of China (Grant No.41175047)+3 种基金the R&D Special Fund for Public Welfare Industry by the Ministry of Finance and the Ministry of Science and Technology (Grant Nos.GYHY201006014 and 20100503310)the Basic Research Project of the State Key Laboratory of Severe Weather (12011LAS-B14)supported by the National Key Basic Research and Development Project of China under Grant Nos.2013CB430103 and 2011CB403405the National Natural Science Foundation of China under Grant Nos.41375058 and 41175065
文摘ABSTRACT Rainfall responses to doubled atmospheric carbon dioxide concentration were investigated through the analysis of two pairs of two-dimensional cloud-resolving model sensitivity experiments. One pair of experiments simulated pre-summer heavy rainfall over southern China around the summer solstice, whereas the other pair of experiments simulated tropical rainfall around the winter solstice. The analysis of the time and model domain mean heat budget revealed that the enhanced local atmospheric warming was associated with doubled carbon dioxide through the weakened infrared radiative cooling during the summer solstice. The weakened mean pre-summer rainfall corresponded to the weakened mean infrared radiative cooling. Doubled carbon dioxide increased the mean tropical atmospheric warming via the enhanced mean latent heat in correspondence with the strengthened mean infrared radiative cooling during the winter solstice. The enhanced mean tropical rainfall was associated with the increased mean latent heat.
基金supported by the Chinese Ministry of Agriculture (948 project No.2006-G1 and ANTA project No.200803034)the Science and Technology Department of Zhejiang Province (No.2006C12091 and 2007C32014)Zhejiang Provincial Natural Science Foundation of China (No.R3080016)
文摘Simultaneous heading of plants within the same rice variety, also refer to heading synchrony, is an important factor that affects simultaneous ripening of the variety. Understanding of the genetic basis of heading synchrony may contribute to molecular breeding of rice with simultaneous heading and ripening. In the present study, a doubled haploid （DH） population, derived from a cross between Chunjiang 06 and TN1 was used to analyze quantitative trait locus （QTL） for heading synchrony related traits, i.e., early heading date （EHD）, late heading date （LHD）, heading asynchrony （HAS）, and tiller number （PN）. A total of 19 QTLs for four traits distributed on nine chromosomes were detected in two environments. One QTL, qHAS-8 for HAS, explained 27.7% of the phenotypic variation, co-located with the QTLs for EHD and LHD, but it was only significant under long-day conditions in Hangzhou, China. The other three QTLs, qHAS-6, qHAS-9, and qHAS-10, were identified under short-day conditions in Hainan, China, each of which explained about 11% of the phenotypic variation. Two of them, qHAS-6 and qHAS-9, were co-located with the QTLs for EHD and LHD. Two QTLs, qPN-4 and qPN-5 for PN, were detected in Hangzhou, and qPN-5 was also detected in Hainan. However, none of them was co-located with QTLs for EHD, LHD, and HAS, suggesting that PN and HAS were controlled by different genetic factors. The results of this study can be useful in marker assisted breeding for improvement of heading synchrony.
基金supported by the National Basic Re-search Program of China (2009CB118301)the National High-Tech Research and Development (863) Programof China (2006AA100101 and 2006AA10Z1E9)the Doctor Foundation of Shandong Agricultural University, China (23023)
文摘In order to understand the genetic basis for Zeleny sedimentation value （ZSV） of wheat, a doubled haploid （DH） population Huapei 3 × Yumai 57 （Yumai 57 is superior to Huapei 3 for ZSV）, and a linkage map consisting of 323 marker loci were used to search QTLs for ZSV. This program was based on mixed linear models and allowed simultaneous mapping of additive effect QTLs, epistatic QTLs, and QTL x environment interactions （QEs）. The DH population and the parents were evaluated for ZSV in three field trials. Mapping analysis produced a total of 8 QTLs and 2 QEs for ZSV with a single QTL explaining 0.64-14.39% of phenotypic variations. Four additive QTLs, 4 pairs of epistatic QTLs, and two QEs collectively explained 46.11% of the phenotypic variation （PVE）. This study provided a precise location of ZSV gene within the Xwmc 93 and GluD1 interval, which was designated as Qzsv-1D. The information obtained in this study should be useful for manipulating the QTLs for ZSV by marker assisted selection （MAS） in wheat breeding programs.
基金supported by the National Key R&D Program of China(2021YFD2200203)Heilongjiang Province Key R&D Program of China(GA21B010)+1 种基金Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)Heilongjiang Postdoctoral Financial Assistance(LBH-Z21097)。
文摘Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants is onerous,and limited biological or breeding work has been carried out on DH individuals or populations.In this study,we provide an effective protocol for poplar haploid induction based on an anther culture method.A total of 96 whole DH plant lines were obtained using an F1hybrid of Populus simonii×P.nigra as a donor tree.The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree.Each DH line displayed distinct features compared to those of the other DH lines or the donor tree.Additionally,some excellent homozygous lines have the potential to be model plants in genetic and breeding studies.
基金supported by the Key Scientific and Technological Project for Agriculture in Zhejiang Province, China (Grant No. 2007C12073)the Basic Research Budget of China National Rice Research Institute (Grant No. 2009RG001-3)
文摘QTLs for drought tolerance at the rice seedling stage were analyzed using a doubled haploid （DH） population consisted of 251 lines from the cross between a japonica parent Maybelle and an indica parent Baiyeqiu. A genetic linkage map with 226 SSR marker loci was constructed. Single-locus analysis following composite interval mapping （CIM） detected a total of five QTLs located on five different chromosomes of rice. Four QTLs were also detected following two-locus analysis, resolving two pairs of epistatic QTLs （E-QTI_s） with positive and additive genetic effects. The results indicated that the alleles from the parent Baiyeqiu contributed DH population to improve drought tolerance at the seedling stage.
文摘Despite significant yield advantage over inbred rice, the adoption rate of hybrid rice in India is very low due to the high seed cost and poor quality of the produce. To alleviate the problem, we initiated a doubled haploid （DH） breeding approach to develop new lines from two elite indica rice hybrids （CRHR5 and CRHR7） through rapid fixation of homozygosity in the recombinants. In vitro culture of the rice anthers resulted in 243 and 186 fertile DH lines of CRHR5 and CRHR7, respectively. Flow cytometric and pollen fertility analyses confirmed the DH ploidy status of the regenerations. Morpho-agronomic evaluation revealed 100% uniformity and stability for all the characters in the DH lines of both hybrids. Nineteen promising DH lines of each hybrid were advanced to A2 generation for yield evaluation. The yield levels of the DH lines ranged from 5 097-6 965 kg/hm^2 for CRHR5 and 5 141-7 235 kg/hm^2 for CRHR7, which were at par or higher than the parental hybrids. Physico-chemical characterization and cooking quality analyses revealed significant and acceptable values for grain length and width, alkali spreading value, amylose content and water uptake ratio of the selected DH lines. Three DH lines, CR5-10, CR5-49, CR5-61 from CRHR5, and four DH lines, CR7-5, CR7-7, CR7-12 and CR7-52 from CRHR7, showed significant grain yield and quality characteristics and have been recommended for multi-location trials for subsequent release as new indica doubled haploid rice varieties.
基金supported by the National Natural Science Foundation of China(31101004,31221004)the National High-Tech R&D Program of China(863 Program,2012AA101201)+2 种基金a fund from Zhejiang Province for public welfare(2014C32013)a special fund for technical innovation team in Zhejiang Province,China(2010R50024)a fund from the Chinese Academy of Agricultural Sciences to the Scientific and Technical Innovation Team
文摘Sheath blight（SB） disease,caused by Rhizoctonia solani Kuhn,is one of the most serious diseases causing rice（Oryza sativa L.） yield loss worldwide.A doubled haploid（DH） population was constructed from a cross between a japonica variety CJ06 and an indica variety TN1,and to analyze the quantitative trait loci（QTLs） for SB resistance under three different environments（environments 1-3）.Two traits were recorded to evaluate the SB resistance,namely lesion height（LH） and disease rating（DR）.Based on field evaluation of SB resistance and a genetic map constructed with 214 markers,a total of eight QTLs were identified for LH and eight QTLs for DR under three environments,respectively.The QTLs for LH were anchored on chromosomes 1,3,4,5,6,and 8,and explained 4.35-17.53%of the phenotypic variation.The SB resistance allele of qHNLH4 from TN1 decreased LH by 3.08 cm,and contributed to 17.53%of the variation at environment 1.The QTL for LH（qHZaLH8） detected on chromosome 8 in environment 2 explained 16.71%of the variation,and the resistance allele from CJ06 reduced LH by 4.4 cm.Eight QTLs for DR were identified on chromosomes 1,5,6,8,9,11,and 12 under three conditions with the explained variation from 2.0 to 11.27%.The QTL for DR（qHZaDR8）,which explained variation of 11.27%,was located in the same interval as that of qHZaLH8,both QTLs were detected in environment 2.A total of six pairs of digenic epistatic loci for DR were detected in three conditions,but no epistatic locus was observed for LH.In addition,we detected 12 QTLs for plant height（PH） in three environments.None of the PH-QTLs were co-located with the SB-QTLs.The results facilitate our understanding of the genetic basis for SB resistance in rice.
文摘This study determined the indirect selection index of doubled haploid(DH)rice using a multivariate analysis approach to select lines adaptive to salinity stress,comprising three experiments.The first experiment involved the selection of good agronomic characters in a field experiment conducted at an experimental station in Bogor,Indonesia.The second experiment involved salinity tolerance screening through hydroponic cultures using 0 and 120 mmol/L NaCl,conducted at a greenhouse in Bogor.The third experiment involved the validation of the indirect adaptability selection index(IASI)through a field experiment in Sukra(saline area).Field experiments followed a randomized complete block design(RCBD),whereas an RCBD nested factorial design was used for the greenhouse experiment.The first and second experiments used 56 DH lines and four check varieties with three replications.In the second experiment,Pokkali and IR29 varieties were also added as tolerant and sensitive checks of salinity,respectively.The third experiment used 28 selected DH lines,Inpari 29 and one sensitive DH line.The good agronomic index(GAI)was 0.465 yield+0.433 number of productive tillers+0.31 number of filled grains.This generated 24 DH rice lines with good agronomic traits.The salinity tolerance index(SaTI)was developed through the average of standardized salinity tolerance score and salinity selection index based on discriminant analysis.This generated 34 DH rice lines with good salinity stress tolerance.The IASI(IASI=GAI–SaTI)selected 28 DH rice lines adaptive to salinity stress and it was considered effective by Sukra validation.
基金JIRCAS International Collaborative Project Fund(B33102-331)Grant Project of Zhejiang Province for International Collaboration(2002AA217111)supported this work
文摘Field performance of whitebacked planthopper （WBPH）-resistance of four phenotypes was evaluated in Chunjiang 06 （C J-06） / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory and ovicidal traits inherited independently from C J-06. WBPH established the highest populations in susceptible DH lines that had neither sucking inhibitorynor ovicidal resistance. Both immigration and subsequent population levels were kept below the damage-causing density in the sucking inhibitory DH lines even under a WBPH outbreak. WBPH could not build up populations in the DH lines having both the sucking inhibitory and ovicidal resistance. Although WBPH immigrated preferentially to non-sucking inhibitory DH lines with ovicidal resistance, subsequent population buildup was significantly suppressed. It was concluded that the differential performance to WBPH-resistance in CJ-06 / TN1 DH lines was primarily due to the sucking inhibitory trait, and complementarity to the ovicidal trait.
文摘A laser diode (LD) pumped Q switched high efficient intracavity frequency doubled Nd ∶YAG laser is reported here. The authors have designed an optical coupler and pointed out that the key to increasing harmonic conversion efficiency is to decrease the loss of fundamental wave. In the experiments, a fundamental mode output laser was acquired. When the pumping power was 12 W, 2.6 W average output power at 1 064 nm with AO Q switch was obtained. 2.1 W average output power at 532 nm was obtained with intracavity frequency doubling, and the highest second harmonic conversion efficiency was 82 0 0.
文摘Stability analysis of grain yield is an efficient tool for the selection of varieties adapted to fairly wide cultivation zone. A study aims to determine adaptability and stability for grain yield and agronomic performance of 10 elite Doubled Haploid (DH) rice genotypes generated through another culture technique, along with local cultivar Umgar as a check under irrigated lowland conditions in three different environments in the central clay plains of the Sudan;during two cropping seasons 2019 and 2020. The trials were conducted in a randomized complete block design with three replications. Grain yield stability was studied, using the Additive Main effect and Multiplicative Interaction (AMMI) model. Bi-plots were developed following GGE bi-plot methodology over the six environments. The combined analysis of variance revealed significant to highly significant (P < 0.001) effects of genotypes, environments, and genotype by environment interaction. Moreover, the analysis of variance based on AMMI indicated significant genotypes, environments, and GE interaction with a total variation of 43.16%, 44.26% and 12.58% respectively. A biplot-AMMI analysis and yield stability index incorporating the AMMI stability value and yield in a single non-parametric index were used to identify the genotypes with the highest and stable yield. The overall mean for grain yield was 5.69 t/ha, with a range of 5.77 to 4.12 t/ha. The genotypes k150147, k150870, k150032, k150912, and k150307 out yielded the local check Umgar by 40%, 38%, 34%, 34% and 33% respectively. The most genotypes were mid-early maturities which were harvested at 107, 113, 108, 109 and 112 days after sowing, respectively. These five genotypes also showed grain yield stability along with their high mean yield performance according to the AMMI analysis and widely adaptable to the tested locations. Therefore, the five out yielding genotypes will be considered for cultivation under irrigated system condition in central clay in the Sudan.
文摘The development of new rice varieties is highly dependent on genetic diversity in desirable agronomic traits. Therefore, this study aimed to identify potential genotypes having the characters of Korean varieties (Tongil-type) and japonica developed through doubled haploid (DH) technology to apply in our breeding materials. 35 elite DH lines derived from another culture of Korean and African rice along with two local checks were planted in a randomized complete block design with three replications during the two seasons of 2019 and 2020. All evaluated genotypes exhibited a wide and significant variation in the ten measured traits. The highest heritability related to high genetic advance was recorded for the number of tiller/plant, grain yield t/ha, number of filled grain per panicle, and thousand grain weights (g). Genotypic coefficient of variation and genetic advance were recorded for number of tiller/plant, number of filled grain per panicle, 1000 grain weight and grain yield t/ha in both seasons. Moreover, there was a highly significant and positive correlation of grain yield with number of filled grain per panicle (0.65), number of tiller/plant (0.64) and number of panicle per m<sup>2</sup> (0.54). Cluster analysis based on grain yield components trait grouped the 37 rice genotypes into four clusters. Cluster B was the largest and consisted of 13 genotypes. Finally, it could be concluded that, based on number of productive tillers, number of filled grain/panicle, number of panicle per m<sup>2</sup>, and grain yield, the lines KF170506, KF170509, KF170542, KF170530, KF170543, KF170500 and KF170510 were high potential for further selection for new type of irrigated rice. In addition, hybridization of these 7 high-yielding could be used to achieve higher heterosis among the genotypes. Furthermore, this evaluation could be useful in developing reliable selection indices for improving rice breeding programs.
文摘It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represents a ran-dom array of the microspore population, i.e.whether gametic selection occurs in androgene-sis. A DH population including 132 lines de-
基金supported by the National Basic Research Program of China(Grant Nos.2013CB922401 and 2012CB821304)the National Natural Science Foundation of China(Grant No.61378040)
文摘We report an enhancement cavity for femtosecond Ti：sapphire laser at the repetition rate of 170 MHz. An enhancement factor of 24 is obtained when the injecting pulses have an average power of 1 W and a pulse duration of 80 fs. By placing a BBO crystal at the focus of the cavity, we obtain a 392-mW intracavity doubled-frequency laser, corresponding to a conversion efficiency of 43%. The output power has a long-term stability with a root mean square （RMS） of 0.036%.
文摘Aiming to join the highincome club within five years The Chinese Communist Party(CCP)released its Proposals for formulating the 14th Five-Year Plan(2021-2025)and the 2035 vision on 3 November 2020.Leaders are aiming to raise the GDP per capita to the level of a“moderately developed country”by 2035;it appears confident that doubling the GDP within 15 years to achieve this is feasible,but has stopped short of making this an official target.
基金the National Natural Science Foundation of China(32321005)the Science and Technology Major Program of Hubei Province(2021ABA011)+1 种基金A.R.F.acknowledges the European Union's Horizon 2020 research and innovation programme,project PlantaSYST(SGA-CSA no.739582 under FPA no.664620)the BG05M2OP001-1.003-001-C01 project,financed by the European Regional Development Fund through the BulgarianEuropean Regional Development Fund through the Bulgarian“Science and Education for Smart Growth"Operational Programme。
文摘Doubled haploid(DH)technology and synthetic apomixis approaches can considerably shorten breeding cycles and enhance breeding efficiency.Compared with traditional breeding methods,DH technology offers the advantage of rapidly generating inbred lines,while synthetic apomixis can effectively fix hybrid vigor.In this review,we focus on(i)recent advances in identifying and characterizing genes responsible for haploid induction(Hl),(ii)the molecular mechanisms of Hl,(ili)spontaneous haploid genome doubling,and(iv)crop synthetic apomixis.We also discuss the challenges and potential solutions for future crop breeding programs utilizing DH technology and synthetic apomixis.Finally,we provide our perspectives about how to integrate DH and synthetic apomixis for precision breeding and de novo domestication.
