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
Kernel size-related traits,including kernel length,kernel width,and kernel thickness,are critical components in determining yield and kernel quality in maize(Zea mays L.).Dissecting the phenotypic characteristics of t...Kernel size-related traits,including kernel length,kernel width,and kernel thickness,are critical components in determining yield and kernel quality in maize(Zea mays L.).Dissecting the phenotypic characteristics of these traits,and discovering the candidate chromosomal regions for these traits,are of potential importance for maize yield and quality improvement.In this study,a total of 139 F2:3 family lines derived from EHel and B73,a distinct line with extremely low ear height(EHel),was used for phenotyping and QTL mapping of three kernel sizerelated traits,including 10-kernel length(KL),10-kernel width(KWid),and 10-kernel thickness(KT).The results showed that only one QTL for KWid,i.e.,qKWid9 on Chr9,with a phenotypic variation explained(PVE)of 13.4%was detected between SNPs of AX-86298371 and AX-86298372,while no QTLs were detected for KL and KT across all 10 chromosomes.Four bulked groups of family lines,i.e.,Groups I to IV,were constructed with F2:3 family lines according to the phenotypic comparisons of KWid between EHel and B73.Among these four groups,Group I possessed a significantly lower KWid than EHel(P=0.0455),Group II was similar to EHel(P=0.34),while both Group III and Group IV were statistically higher than EHel(P<0.05).Besides,except Group IV exhibited a similar KWid to B73(P=0.11),KWid of Groups I to III were statistically lower than B73(P<0.00).By comparing the bulked genotypes of the four groups to EHel and B73,a stable chromosomal region on Chr9 between SNPs of AX-86298372 to AX-86263154,entirely covered by qKWid9,was identified to link KWid with the positive allele of increasing phenotypic effect to KWid from B73,similar to that of qKWid9.A large amount of enzyme activity and macromolecule binding-related genes were annotated within this chromosomal region,suggesting qKWid9 as a potential QTL for KWid in maize.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.
基金the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0583)Maize Germplasm Resources Protection Project,and Fundamental Research Funds for the Central Universities of Southwest University(SWU118087,XDJK2017C031,XDJK2017D072)。
文摘Kernel size-related traits,including kernel length,kernel width,and kernel thickness,are critical components in determining yield and kernel quality in maize(Zea mays L.).Dissecting the phenotypic characteristics of these traits,and discovering the candidate chromosomal regions for these traits,are of potential importance for maize yield and quality improvement.In this study,a total of 139 F2:3 family lines derived from EHel and B73,a distinct line with extremely low ear height(EHel),was used for phenotyping and QTL mapping of three kernel sizerelated traits,including 10-kernel length(KL),10-kernel width(KWid),and 10-kernel thickness(KT).The results showed that only one QTL for KWid,i.e.,qKWid9 on Chr9,with a phenotypic variation explained(PVE)of 13.4%was detected between SNPs of AX-86298371 and AX-86298372,while no QTLs were detected for KL and KT across all 10 chromosomes.Four bulked groups of family lines,i.e.,Groups I to IV,were constructed with F2:3 family lines according to the phenotypic comparisons of KWid between EHel and B73.Among these four groups,Group I possessed a significantly lower KWid than EHel(P=0.0455),Group II was similar to EHel(P=0.34),while both Group III and Group IV were statistically higher than EHel(P<0.05).Besides,except Group IV exhibited a similar KWid to B73(P=0.11),KWid of Groups I to III were statistically lower than B73(P<0.00).By comparing the bulked genotypes of the four groups to EHel and B73,a stable chromosomal region on Chr9 between SNPs of AX-86298372 to AX-86263154,entirely covered by qKWid9,was identified to link KWid with the positive allele of increasing phenotypic effect to KWid from B73,similar to that of qKWid9.A large amount of enzyme activity and macromolecule binding-related genes were annotated within this chromosomal region,suggesting qKWid9 as a potential QTL for KWid in maize.
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。
