吉林省中晚熟水稻品种耐冷性鉴定结果与分析

Identification of Cold Tolerance of Middle-late Maturing Rice Varieties in Jilin Province

低温冷害是造成水稻减产的重要因素。通过测定不同温度下21个水稻品种丙二醛(MDA)含量、叶绿体色素含量、抗坏血酸过氧化物酶(APX)活性、谷胱甘肽过氧化物酶(GPX)活性等生理生化指标的变化,筛选出耐冷性强的品种,为吉林省耐冷水稻品种选育提供理论依据和生产实践支撑。经低温处理后,所有供试水稻品种MDA含量均明显增加;多数品种(品系)叶绿体色素均有增加的趋势,但不显著,表明水稻幼苗叶绿体色素在低温逆境胁迫下并没有发生显著损伤;测定了6个品种经低温处理后的抗坏血酸过氧化物酶(APX)与谷胱甘肽过氧化物酶(GPX)活性,活性均显著增加,表明这2种酶对水稻耐冷性起重要作用。MDA与叶绿体色素、APX及GPX之间的相关性未达到显著水平,需要进一步研究。经鉴定,宏科67、通禾16-8037、通科27、宏科87和辉粳7等5个品种耐冷性较强,可作为耐冷育种的亲本;吉玉粳、铁19、廪实698、吉粳507和秋田小町等5个品种耐冷性较弱。

Chilling damage is one of the important factors causing rice yield reduction. The malondialdehyde (MDA), chloroplast pigments contents, ascorbate peroxidase (APX) and glutathione peroxidase (GPX) activity of twenty one middle-late maturing rice varieties under different temperatures were determined using test box. The objective is to select the cultivars with higher cold tolerance in terms of the determined parameters, provide theoretical basis and production practice for the selection and breeding of cold-tolerant rice varieties in Jilin province. The results showed that, the MDA content of all tested rice varieties increased significantly after low temperature treatment. The chloroplast pigments of most varieties (lines) have an increasing trend, but not significant, it showed that chloroplast pigments of rice seedlings did not undergo significant damage under low temperature stress. Six varieties were selected and treated at low temperature, and their APX and GPX activities were significantly increased, it suggested that both played an important role in cold tolerance of rice. The correlation between MDA and chloroplast pigments, APX and GPX did not reach significant levels, and further research is needed. The identification results showed that Hongke 67, Tonghe 16-8037, Tongke 27, Hongke 87 and Huigeng 7 had strong cold tolerance and could be used as cold-resistant breeding parents. Five varieties including Jiyugeng, Tie 19, Bingshi 698, Jigeng 507 and Akita Komachi have weak cold tolerance.