从现有商业品种中筛选耐高温水稻品种

Screening of high temperature tolerant rice(Oryza Sativa L.)varieties from current commercial varieties and materials

通过人工气候室模拟当地高温年份日温度变化,采用梯级温度法对收集到的14个水稻(Oryza sativa L.)品种进行花期高温处理,测定不同温度下的受精率,计算各品种的耐热指数和耐热综合指数,判定各品种的耐热性。结果表明,荃优华占和全两优华占的耐热综合指数在2.5以上,在日平均气温为30.0、32.0℃的处理下耐热指数均在0.75以上;日平均气温为34.0℃时,其耐热指数显著下降。其他品种的耐热综合指数均低于2.5,且日平均气温为32.0℃时,其耐热指数在0.51及以下。筛选出了荃优华占和全两优华占2个较耐热品种,可安全地用于大面积商业化生产。对于其他耐热性稍低的品种(2.0≤IHTI<2.5),在推广过程中,需探讨品种避热(如适当推迟栽培期)技术和措施;而对于综合耐热指数低的品种(IHTI<2.0),应限制其在热害常发地区的推广。

By simulating the daily temperature change pattern of typical local high temperature stress in a climate chamber,14 rice(Oryza sativa L.)varieties were treated with high temperature at flowering stage by cascade-temperature testing method.Assessing the fertility rate of varieties under different temperatures,the heat tolerance index(HTI)and integrated heat tolerance index(IHTI)of each variety were calculated,and the heat tolerance comprehensive index was used as the final index to determine the heat tolerance of rice varieties.The results showed that the comprehensive heat resistance index of Quanyouhuazhan and Quanliangyouhuazhan were greater than 2.5,and the heat resistance index was greater than 0.75 when the daily average temperature were 30.0℃and 32.0℃,re⁃spectively.When the daily average temperature was 34.0℃,the heat resistance index decreased significantly.The comprehensive heat tolerance index of other varieties was lower than 2.5,and when the daily average temperature was 32.0℃,the heat resistance index was 0.51 or less.Two more tolerant varieties of Quanyouhuazhan and Quanliangyouhuazhan were selected,which can be used for ex⁃tension in commercial production in greater area in the future safely.Suitable heat avoidance measures should be taken for those variet⁃ies with 2.0≤IHTI<2.5,and for varieties with IHTI<2.0,their commercial use should be limited to spread in areas where heat dam⁃age often occurs.