JCR-Genetic effects conferring heat tolerance in upland cotton (Gossypium hirsutum L.)
摘要：
[背景] 气候变化，特别是全球变暖，对大田作物的产量造成严重的威胁，并对许多国家和地区的作物种植模式产生了巨大影响。自2015年以来，由于在棉花关键生育期（开花期和结铃期）的气温升高，巴基斯坦的棉花产量从140万包下降到100万包。本文采用世代均值分析法对2个杂交组合（即VH-282×FH-142和DNH-40×VH-259）的6个群体（P1，P2，F1，F2，BC1和BC2）的耐热性遗传效应进行了研究。
[结果] 结果表明，在高温胁迫下，组合1大部分性状的表现优于比组合2。高温胁迫下，铃重和衣分（GOT）受影响较大，二者与相对细胞损伤（Relative cell injury，RCI）呈负相关。铃重、纤维长度、纤维强度和纤维细度均受非加性基因作用控制，而RCI主要受加性效应影响。除RCI外，其它性状均表现为较低遗传进度值和较高的广义遗传力，这也证实了非加性遗传效应的作用。组合1的正常条件下的铃重、纤维强度，高温条件下纤维整齐度和RCI，组合2的铃重、衣分在正常、高温条件下均受加性效应和显性效应的显著影响。高温条件下纤维整齐度和RCI受影响。正常条件下和高温胁迫下，铃重的群体中亲优势和超亲优势均较为明显，这给育种者利用该资源提高铃重提供了机会。
[结论] 组合1在高温胁迫下表现较好，可用于耐热品种的选育。RCI受加性基因作用的影响，可以利用这一性状筛选耐高温的棉花材料，而其他性状主要受非加性基因作用控制，基于这些性状的选择应推迟到较高世代。
关键词：高温胁迫；遗传力；杂种优势；相对细胞损伤；陆地棉
Abstract:
[Background] Climate change and particularly global warming has emerged as an alarming threat to the crop productivity of field crops and exerted drastic effects on the cropping patterns. Production of cotton has been dropped down to one million bales from 1.4 million bales since 2015 in Pakistan due to the increase in temperature at critical growth stages, i.e., flowering and boll formation. Keeping in view the importance of cotton in the country, this study was conducted to investigate the genetic effects conferring heat tolerance in six populations (P1, P2, F1, F2, BC1 and BC2) developed from cross-1 and cross-2, i.e., VH-282?×?FH-142 and DNH-40?×?VH-259.
[Results] The results revealed that cross-1 performed better in heat stress as compared with cross-2 for majority of the traits recorded. Boll weight and ginning outturn (GOT) were highly effected under heat stress and had negative correlation with Relative cell injury (RCI). Boll weight, fiber length, fiber strength and fiber fineness were under the control of non-additive gene action, whereas RCI was controlled by additive gene effects. Lower values of genetic advance coupled with higher values of broad sense heritability for these traits except RCI confirmed the role of non-additive genetic effects. Duplicate types of epistasis were recorded for fiber strength in cross-1 in normal condition. However, complementary type of non-allelic interaction was recorded for fiber strength under normal condition, fiber fineness and RCI under heat stressed condition in cross-1. Likewise, boll weight, GOT and fiber length in populations derived from cross-2 in normal condition were also under the influence of complementary type of non-allelic interaction. Significant differences among values of mid parent and better parent heterosis for boll weight in both normal and heat stress condition provided the opportunity to cotton breeders for utilization of this germplasm for improvement of this trait through exploitation of heterosis breeding.
[Conclusion] Cross-1 performed better in heat stress and could be utilized for development of heat tolerant cultivar. RCI was under the influence of additive gene action, so one can rely on this trait for screening of large number of accessions of cotton for heat stress. While other traits were predominantly controlled by non-additive gene action and selection based on these should be delayed in later generations.
Keywords: Heat stress, heritability, heterosis, relative cell injury, upland cotton
Title: Genetic effects conferring heat tolerance in upland cotton (Gossypium hirsutum L.)
Authors: SALMAN Muhammad, ZIA Zia Ullah, RANA Iqrar Ahmad, MAQSOOD Rana Haroon, AHMAD Saghir, BAKHSH Ali, AZHAR Muhammad Tehseen
Journal of Cotton Research. 2019; 2: 9
https://doi.org/10.1186/s42397-019-0025-2
https://jcottonres.biomedcentral.com/articles/10.1186/s42397-019-0025-2
