A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was iden...A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was identified in a BC3F8 population derived from a cross of Nipponbare as the recipient with Xihui 18 as the donor parent. Z1364 carried three substitution segments distributed on chromosomes 1, 6, and 8. The mean substitution length was 1.19 Mb. Of 17 QTL identified on the substitution segments, qSP1 for spikelets per panicle, qSSD1 for seed-set density, and qNSB1 for number of secondary branches explained respectively 57.34%, 87.7%, and 49.44% of the corresponding phenotypic variance and were all linked to RM6777. Chi-square analysis showed that the increased kernel number in Z1364 was inherited recessively by a single gene. By fine mapping, qSP1 was delimited to a 50-kb region on the short arm of chromosome 1. Based on DNA sequence, a previously uncharacterized rice homolog of Arabidopsis thaliana AT4G32551 was identified as a candidate gene for qSP1 in which mutation increases the number of spikelets and kernels in Z1364. qSP1 was expressed in all tissues, but particularly in 1-cm panicles. The expression levels of OsMADS22, GN1A, and DST were upregulated and those of LAX2, GNP1, and GHD7 were downregulated in Nipponbare. These results provide a foundation for functional research on qSP1.展开更多
Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful ...Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues ></span><span style="font-family:""> </span><span style="font-family:Verdana;">1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).展开更多
为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量...为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量55%~65%;正常灌水,田间持水量75%~85%3个灌溉水平,编号W_(0)、W_(1)、W_(2),组合为N_(0)W_(0)、N_(0)W_(1)、N_(0)W_(2)、N_(1)W_(0)、N_(1)W_(1)、N_(1)W_(2)等6个水氮处理,测定比较不同水氮处理的叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)、水分利用效率(WUE),脯氨酸、丙二醛、可溶性糖、淀粉含量,株产及果实品质。结果表明,水氮互作下,花期叶片Pn、Gs、Ci和WUE随水分增加呈先增加后减小变化,Tr呈递增或递减趋势;果实膨大期、果实油分积累期的Pn、Gs、Ci、Tr、WUE都呈现先增加后减少趋势。施氮处理后光合效应提升,花期Pn、Ci、Tr等光合指标受N和W影响显著,果实膨大期和果实油分积累期灌溉方式W为主要影响因子,干旱或重度水分胁迫均会显著降低Pn。适量灌溉和施氮条件下,叶片脯氨酸、丙二醛、可溶性糖、淀粉含量降低,这能减缓膜过氧化程度并调节渗透压,缓解干旱胁迫对澳洲坚果叶片产生的损害。花期和果实膨大期叶片丙二醛、可溶性糖、淀粉含量受N和W显著影响,存在显著交互作用。其中,N_(1)W_(1),即施氮肥300 g/株+适当灌水,田间持水量55%~65%处理,花期、果实膨大期和果实油分积累期光合生理效应最优,相较于其他处理表现出更强的抗环境胁迫能力,可促进澳洲坚果生长和果实发育,出仁率较高,株产、一级果仁质量、一级果仁率均最高。展开更多
基金supported by the National Key Research Plan Project (2017YFD0101107)the Chongqing Science and Technology Commission Special Project (cstc2016shmsztzx0032)the Southwest University Innovation Team Project (XDJK2017A004)
文摘A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was identified in a BC3F8 population derived from a cross of Nipponbare as the recipient with Xihui 18 as the donor parent. Z1364 carried three substitution segments distributed on chromosomes 1, 6, and 8. The mean substitution length was 1.19 Mb. Of 17 QTL identified on the substitution segments, qSP1 for spikelets per panicle, qSSD1 for seed-set density, and qNSB1 for number of secondary branches explained respectively 57.34%, 87.7%, and 49.44% of the corresponding phenotypic variance and were all linked to RM6777. Chi-square analysis showed that the increased kernel number in Z1364 was inherited recessively by a single gene. By fine mapping, qSP1 was delimited to a 50-kb region on the short arm of chromosome 1. Based on DNA sequence, a previously uncharacterized rice homolog of Arabidopsis thaliana AT4G32551 was identified as a candidate gene for qSP1 in which mutation increases the number of spikelets and kernels in Z1364. qSP1 was expressed in all tissues, but particularly in 1-cm panicles. The expression levels of OsMADS22, GN1A, and DST were upregulated and those of LAX2, GNP1, and GHD7 were downregulated in Nipponbare. These results provide a foundation for functional research on qSP1.
文摘Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues ></span><span style="font-family:""> </span><span style="font-family:Verdana;">1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).
文摘为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量55%~65%;正常灌水,田间持水量75%~85%3个灌溉水平,编号W_(0)、W_(1)、W_(2),组合为N_(0)W_(0)、N_(0)W_(1)、N_(0)W_(2)、N_(1)W_(0)、N_(1)W_(1)、N_(1)W_(2)等6个水氮处理,测定比较不同水氮处理的叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)、水分利用效率(WUE),脯氨酸、丙二醛、可溶性糖、淀粉含量,株产及果实品质。结果表明,水氮互作下,花期叶片Pn、Gs、Ci和WUE随水分增加呈先增加后减小变化,Tr呈递增或递减趋势;果实膨大期、果实油分积累期的Pn、Gs、Ci、Tr、WUE都呈现先增加后减少趋势。施氮处理后光合效应提升,花期Pn、Ci、Tr等光合指标受N和W影响显著,果实膨大期和果实油分积累期灌溉方式W为主要影响因子,干旱或重度水分胁迫均会显著降低Pn。适量灌溉和施氮条件下,叶片脯氨酸、丙二醛、可溶性糖、淀粉含量降低,这能减缓膜过氧化程度并调节渗透压,缓解干旱胁迫对澳洲坚果叶片产生的损害。花期和果实膨大期叶片丙二醛、可溶性糖、淀粉含量受N和W显著影响,存在显著交互作用。其中,N_(1)W_(1),即施氮肥300 g/株+适当灌水,田间持水量55%~65%处理,花期、果实膨大期和果实油分积累期光合生理效应最优,相较于其他处理表现出更强的抗环境胁迫能力,可促进澳洲坚果生长和果实发育,出仁率较高,株产、一级果仁质量、一级果仁率均最高。
