田间杂交水稻单年单点5种不同逆境的批量筛选及聚类分析
Mass screening and cluster analysis for tolerance to stress of hybrid rice variety under field conditions
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摘要: 以48个杂交水稻组合(sz744~sz791)为供试材料, 分别以三系杂交稻“汕优63”和两系杂交稻“两优培九”为对照材料, 在单年水稻生育后期, 在同一实验田中, 分别对其耐高光强、耐低光强、耐水分匮乏、耐高肥及抗早衰等特性进行筛选, 并在收获后考察其结实率。结果表明: 供试水稻材料对不同逆境的耐性表现不同, 结合叶绿素含量、植株干重、穗期田间晒田时叶片Fv/Fm、茎伤流、硝酸还原酶活性等逆境筛选指标以及后期结实率的联合筛选, 通过联合聚类分析, 可将供试水稻对上述5种逆境的耐性分为5类型, 其中结实率与高光强下叶绿素含量变化、叶片硝酸还原酶活性及孕穗期剑叶叶绿素含量的相关系数分别为0.426**、0.295*和0.566**, 水稻当年的结实率也可作为水稻广适性筛选的参考指标Abstract: Using 2 high-yield hybrid rice varieties (the 3-line hybrid rice variety “Shanyou 63” and 2-line hybrid rice variety “Liangyoupeijiu”) as the control (CK), selected growth and physiological parameters including chlorophyll content, dry-weight, Fv/Fm, stem bleeding and nitrate reductase activity (NRA) of 48 rice materials (sz744~sz791) were measured at flowering stage in a one-year field experiment to determine the material’s tolerance to high light intensity, low light intensity, drought, high nitrogen application and early aging. Seed-setting rates of the rice plants were also observed after harvesting. The results show different tolerance performances to above mentioned stresses of the tested materials. Clustering analysis on different performance combinations of the rice to the stresses classifies the materials into 5 types. Based on the indices, the correlation coefficient of seed-setting rate to change in chlorophyll content under high light intensity, leaf NRA at heading stage, and chlorophyll content of flag leaf at booting stage are respectively 0.426**, 0.295* and 0.566**. Rice seed-setting rate in one year may also be an important eurytropic adaptability index.