低温胁迫对大豆幼苗形态生理指标及籽粒产量的影响

黑龙江省大豆苗期低温冷害频发，为了明确大豆苗期低温胁迫对籽粒产量是否有影响，试验采用盆栽方法，在大豆V1 期将自然环境下生长的幼苗置于人工气候箱进行不同温度处理，分别为6℃，10℃和25℃（对照），处理48 h 后测定叶片鲜重、子叶鲜重、茎鲜重、根系鲜重及叶片叶绿素含量，然后将幼苗转移到盆栽盆中生长，成熟期测定大豆籽粒产量及产量构成因子。结果表明：大豆幼苗期低温胁迫显著降低了不同大豆品种叶片鲜重、子叶鲜重、茎鲜重、根系鲜重及叶绿素含量；随着温度的降低，耐低温大豆品种‘合农60’的形态及生理指标降低幅度要低于低温敏感型大豆品种‘黑农48’。苗期低温胁迫未显著降低耐低温大豆品种‘合农60’株荚数、株粒数、百粒重及籽粒产量，但显著降低了低温敏感型大豆‘黑农48’的株荚数、株粒数、百粒重及籽粒产量。研究得出结论为苗期大豆低温胁迫不利于大豆籽粒产量形成，显著降低低温敏感品种大豆籽粒产量。

Cold Stress Affects Morphological and Physiological Indexes of Soybean Seedling and Seed Yield

Chilling damage often happens at soybean seedling stage in Heilongjiang. To clarify the effect of chilling damage at seedling stage on soybean yield, a pot experiment was conducted. At V1 stage, soybean seedlings in the natural environment were moved into artificial climate cabinet for different temperature treatments, including 6℃, 10℃, and 25℃ (CK). After 48 h, fresh leaf weight, fresh cotyledon weight, fresh stem weight, fresh root weight and chlorophyll content of soybean seedling were determined. And then soybean seedlings were transferred to bigger pot for growth. The seed yield and yield components were measured at maturity stage. The results showed that cold stress significantly decreased fresh leaf weight, fresh cotyledon weight, fresh stem weight, fresh root weight and chlorophyll content. Morphological and physiological parameters of cold- resistant variety‘Henong60’decreased much more slowly than cold- sensitive variety ‘Heinong48’with the temperature decrease. Cold stress at seedling stage did not significantly decrease pod number per plant, seed number per plant, 100-seed weight and seed yield of‘Henong60’. However, pod number per plant, seed number per plant, 100-seed weight and seed yield of‘Heinong48’were significantly decreased by cold stress at seedling stage. Therefore, the cold stress at soybean seedling stage is not beneficial to the formation of seed yield and can significantly decrease the seed yield of cold-sensitive variety.