Biswas Partha S, Khatun Hasina, Das Nomita, Sarker Md Mahathir, Anisuzzaman M
International Rice Research Institute, Philippines, Los Baños, Philippines.
Bangladesh Rice Research Institute, Gazipur, 1701 Bangladesh.
3 Biotech. 2017 Dec;7(6):359. doi: 10.1007/s13205-017-0993-1. Epub 2017 Oct 3.
Yellowing, stunting, and seedling death associated with cold stress is a common problem in many Asian countries for winter rice cultivation. Improvement of cultivars through marker-assisted selection of QTLs for cold tolerance at seedling stage from locally adapted germplasm/cultivar is the most effective and sustainable strategy to resolve this problem. A study was undertaken to map QTLs from 151 progenies of a cross between a cold susceptible variety, BR1 and a locally adapted traditional cultivar, Hbj.BVI. A total of six significant QTLs were identified for two cold tolerance indices-cold-induced leaf discoloration and survival rate after a recovery period of seven days on chromosomes 6, 8, 11, and 12. Among these QTLs, -- and -- being co-localized into RM7027-RM339 on chromosome 8 and -- and -- into RM247-RM2529 on chromosome 12 showed 12.78 and 14.96% contribution, respectively, to the total phenotypic variation for cold tolerance. Validation of QTL effect in BCF population derived a cross between a cold susceptible BRRI dhan28 and Hbj.BVI showed dominating effect of -- on cold tolerance at seedling stage and it became stronger when one or more other QTLs were co-segregated with it. These results suggest that the QTLs identified in this study are stable and effective on other genetic background also, which warrant the use of these QTLs for further study aiming to cultivar development for seedling stage cold tolerance.
在许多亚洲国家，与冷胁迫相关的叶片发黄、生长受阻和幼苗死亡是冬稻种植中常见的问题。通过对本地适应种质/品种的苗期耐冷性QTL进行标记辅助选择来改良品种，是解决这一问题最有效且可持续的策略。本研究对冷敏感品种BR1与本地适应的传统品种Hbj.BVI杂交产生的151个后代进行了QTL定位。在第6、8、11和12号染色体上，共鉴定出6个与两个耐冷性指标（冷诱导叶片变色和7天恢复期后的存活率）相关的显著QTL。在这些QTL中，位于第8号染色体上RM7027 - RM339区间的——和——以及位于第12号染色体上RM247 - RM2529区间的——和——分别对耐冷性的总表型变异贡献了12.78%和14.96%。在冷敏感品种BRRI dhan28与Hbj.BVI杂交衍生的BCF群体中对QTL效应进行验证，结果表明——在苗期耐冷性上具有主导作用，当一个或多个其他QTL与之共分离时，其作用更强。这些结果表明，本研究中鉴定出的QTL在其他遗传背景下也稳定有效，这为利用这些QTL进行旨在培育苗期耐冷品种的进一步研究提供了依据。
