长江中游区冬油菜抗冻性的光合及生物学指标筛选与分析

筛选建立低温前简易的作物抗冻性生物学特征指标识别体系对于作物抗冻育种和栽培均具有重要意义。以15个甘蓝型冬油菜品种为材料,研究油菜品种抗冻性与低温前生物学性状、叶绿素含量、光合指标之间的关系。结果表明,不同品种间抗冻性差异较大,以中双9号、皖油18、陕油8号等品种抗冻能力较强,中油杂5号和湘油17等抗冻能力较差。关联度分析结果表明,油菜冬前生物学性状及生理指标中,与冻害指数的关联度大小依次为地上部含水率>地上鲜质量>蒸腾速率(Tr)>株高>气孔导度(Gs)>开展度>光合速率(Pn)>绿叶数>叶绿素含量>地下部含水率>胞间CO2摩尔分数(Ci)。其中地上部含水率、地上鲜质量和蒸腾速率(Tr)与冻害指数呈极显著正相关,株高、气孔导度呈显著正相关,其他指标与冻害指数相关关系均不显著。相关性和关联度分析结果表明,地上部含水率、地上部鲜质量、蒸腾速率(Tr)和株高等光合及生物学性状可以作为油菜抗冻性的筛选指标。

Screening and Analyzing Photosynthetic and Biological Indexes of Winter Rapeseed (Brassica napus L.) Freezing Resistance in the Middle Reaches of Yangtze River

It is important to establish and screen the systematic feature index of freezing resistance of B.napus for freezing-resistance breeding and cultivation.We used 15 winter rapeseed as materials,studied the relationship between freezing damage index and photosynthesis,biological characteristics,etc.The results showed that,there was significant difference of freezing resistance among cultivars.The cultivars such as Zhongshuang No.9,Wanyou No.18 etc.were strong freezing resistance,while cultivars such as Zhongyouza No.5,Xiangyou No.17 etc.were weak freezing resistance.The order of the correlation degree between freezing resistance and photosynthesis and biological characteristics analyzed by grey correlation degree was: shoot water content>shoot mass>transpiration rate(Tr)>plant hight>stomatal conductance(Gs)>leaf expansion>net photosynthetic rate(Pn)>number of green leaves>SPAD value>root water content>mole fraction of intercellular CO2(Ci).Among them,a significant positive correlation existed between freezing damage index and shoot water content,shoot mass and transpiration rate(Tr),while the significant positive correlation between freezing damage index and plant height and stomatal conductance(Gs) was at a level of 0.05.Other characteristics such as leaf expansion,Pn,number of green leaves,etc.were non-significant.Therefore,shoot water content,shoot mass,transpiration rate(Tr) and plant height could be the evaluation indexes for freezing resistance screening.