云南稻核心种质孕穗期耐冷性状间的相关性与生态差异

 以548份云南地方稻核心种质为材料在昆明自然低温平均18℃(冷害)和温室23℃条件下进行了孕穗期耐冷性状间的相关性及其生态差异分析。 冷害条件下云南稻核心种质形态性状均与孕穗期耐冷性有关，耐冷指标性状每穗实粒数、穗颈长、每穗秕粒数、穗下节长、花药长及其体积、1~2节长与结实率呈较高的(≥0.549**)极显著(n=548, R0.01=0112**)相关；相反，温室条件下仅有每穗实粒数、秕粒数与结实率相关系数较高。 冷害条件下云南稻核心种质的每穗实粒数、花药体积、穗下节长、穗颈长与结实率大小在5个稻作区间的变化规律呈现一致性，这种差异既与株高、穗下节长、穗颈长和1~2节长等耐冷性状有关，又与地州或稻区间的气候和生态差异相联系；而温室条件下云南稻核心种质耐冷性状5个稻作区间差异不大，地州间结实率差异是每穗实粒数和秕粒数差异所致，而与耐冷性状关系不大。

Ecological Difference and Correlation Among Cold Tolerance Traits at the Booting Stage for Core Collection of Rice Landrace in Yunnan, China

Some cold tolerance traits at the booting stage were evaluated based on 548 accessions core collection of rice landrace in Yunnan under natural low temperature (18℃, cold damage) and greenhouse (23℃). All the morphological traits of core collection were closely related to cold tolerance traits at the booting stage under cold damage conditions, with higher significant correlation coefficients(≥0.549 ** ) between seed setting rate and eight cold tolerance index traits including filled grain number per panicle, peduncle length, unfilled grain number per panicle, length of the node under panicle, anther length, anther volume, and first to second node length. On the contrary, there were only significant correlation (r>0.6) between seed setting rate and filled grain number per panicle, unfilled grain number per panicle, and low correlation (≤0.292 ** ) between other traits and seed setting rate under greenhouse. There was a similar changing trend among five rice ecological regions based on five cold tolerance index traits, i.e. filled grain number per panicle, anther volume, length of the node under panicle, peduncle length and first to second node length. For 16 prefectures or cities in Yunnan, these differences were closely associated not only with plant height, length of the node under panicle, peduncle length and first to second node length, but also with the climate and ecological difference.On the contrary, there was no relationship in cold tolerance traits among rice ecological regions or prefectures under greenhouse conditions except for filled grain number per panicle and unfilled grain number per panicle.