江淮地区低温冻害对不同类型小麦幼茎细胞结构的影响

为了解冻害对不同基因型稻茬小麦苗期幼茎细胞结构的影响,选用皖麦50(半冬性品种)、皖麦48(弱春性品种)和郑麦9023(春性品种)为材料,在低温条件下连续用显微镜观测幼茎分蘖节薄壁细胞质壁分离变化情况。结果表明,在低温天气发生的初期,三个品种只发生了轻微的质壁分离,回暖后可恢复。当0℃以下低温持续10d以上时,质壁分离现象加重,皖麦48和郑麦9023分蘖节薄壁细胞原生质体出现不规则收缩,导管和筛管破裂,细胞失水收缩率最高达到30%左右,明显高于皖麦50。不同品种细胞失水收缩最大值均出现在连续低温之后,与最低温度出现时间不一致。

Effection of Freeze Injury on Cell Structure in Tiller Node of Different Types of Winter Wheat in Yangtze Huaihe Region

The cell structure in the tiller nodes of winter wheat cultivars under rice stubble was observed with semi-winter wheat cultivar Wanmai 50,semi-spring wheat cultivar Waimai 48 and spring wheat cultivar Zhengmai 9023 as materials,using electron microscope to investigate the differences in the cell plasmolysis of different winter wheat cultivars upon cold stress during January 2008.The results showed that slight plasmolysis occurred in the tiller node cells of all 3 cultivars at early stage of low temperature period and the cells could recover when temperature raised.Serious plasmolysis could be observed when the duration of low temperature(below 0℃) was more than 10 days.Irregular shrinkage of protoplast and rupture of vessel and sieve elements were observed in the tiller nod cells of Wanmai 48 and Zhengmai 9023.The maximum ratios of parenchyma cell shrinkage were about 30% in the tiller nodes of Wanmai 48 and Zhengmai 9023,and these values were higher than those of Wanmai 50.Additionally,all the maximum ratios of parenchyma cell shrinkage appeared not at the lowest temperature day but after the duration of low temperature in all tested cultivars.