14个亚洲国家水稻种质资源的苗期耐寒性评价

Evaluation of Cold Tolerance at Seedling Stage of Oryza sativa L.Germplasm Resources from 14 Asian Countries

【目的】筛选耐寒性水稻品种。【方法】以广泛代表性的14个亚洲国家187个水稻核心种质为研究对象,根据种内群体关系和地理位置将其分为4个平行组;分别对4个平行组的三叶期幼苗进行4℃低温处理,时间梯度设为24、36、48和60 h,7 d缓苗期后统计其秧苗黄叶率并鉴定耐寒等级。【结果】根据黄叶率百分比可以精准鉴定水稻的5个耐寒等级,且粳稻的耐寒性普遍比籼稻强。11个强耐寒品种主要分布于高纬度或高海拔地区。4℃处理24和36 h后的黄叶率在不同品种间呈现丰富多样性,该耐寒处理方式获得的表型性状适合全基因组关联分析。【结论】品种之间耐寒性的差异不仅由遗传因素决定,还与其地理分布和当地种植策略相关。本研究初步筛选出11个苗期耐寒水稻品种,可为耐寒种质资源的遗传改良和分子育种提供参考。

[Purpose]To select cold-tolerant rice varieties.[Method]187 cultivated rice(Oryza sativa L.)germplasm resources from 14 Asian countries were taken as research objects.According to population relationship of intraspecies group and geographical location,they were roughly divided into 4 parallel groups.The three-leaf stage seedlings were treated at 4℃for 24,36,48 and 60 h,respectively,and the yellow leaf rate was counted after the period and the cold tolerance level was identified.[Result]According to the percentage of yellow leaf rate,the five cold tolerance grades of rice could be accurately identified.O.sativa ssp.japonica had better cold tolerance than O.sativa ssp.indica.The 11 strong cold-tolerant varieties were mainly distributed in high latitude or high altitude regions.The results showed that the leaf yellow rate had good diversity at 24 h and 36 h at 4℃,which were suitable for the whole genome-wide association analysis.The difference in cold tolerance between varieties is determined not only by genetic factors,but also by their geographical distribution and local planting strategy.[Conclusion]A total of 11 low-temperature resistant rice cultivars were screened in different treatment groups,which could provide reference for genetic improvement and molecular breeding of cold-tolerant germplasm resources.