近十年新疆北疆主栽棉花种子低温萌发能力差异评价

Evaluation of Seed Germination of Main-cultivated Cotton under Low Temperature in Northern Xinjiang in Recent Ten Years

【目的】研究低温对棉花种子萌发特性的影响,筛选耐冷种质资源,探讨模糊隶属函数法在棉花种子低温耐冷性鉴定的应用。【方法】以近10年新疆北疆主栽的棉花品种(系)为试材,测试种子发芽指标对不同温度的响应变化,基于发芽指标和相对发芽指标(耐冷系数)的模糊隶属函数值法,对试材的低温萌发能力差异进行评价。【结果】随着胁迫增强,棉花种子的萌发能力受到显著抑制,种子平均发芽速度随温度上升呈下降趋势,而其它发芽指标均随温度上升呈显著增高。棉花种子的耐冷萌发力均与其萌发指标显著正相关。同一低温下两种隶属函数法对种子低温萌发能力的鉴定结果高度一致,但不同低温下参试棉花种子的萌发力有所差异。15℃种子萌发强的为中棉所36号和新陆早46号,20℃为新陆早25号、新陆早42号、新陆早36号、新陆中26号、中棉所36号、新陆早41号和新陆早35号。低温下,除了平均发芽速度,其它棉花种子的发芽指标间及其与种子萌发力两两极显著相关。采用逐步回归法建立了不同低温下棉花种子萌发耐冷性的鉴定模型,其中15℃为Y=0.01+0.022*发芽指数,20℃为Y=-0.046+0.002*发芽率+0.005*种子萌发指数。【结论】萌芽期种子耐冷性强的材料为中棉所36号和新陆早46号。基于发芽指标的模糊隶属函数法可以有效用于棉花种子萌芽的耐冷性鉴定评价。

【Objective】In order to understand the effect of low temperature on seed germination and to explore the suitable methods for identifying chilling tolerance of cotton seeds.【Method】Some mainly-cultivated cottons were selected as the experimental materials in northern Xinjiang in recent ten years,responses of seed germination characteristics to different temperature were studied,and their germination abilities were also evaluated using germination parameters and relative germination parameters（ cold tolerance coefficient） according to subordinative function method under low temperature,respectively. 【Result 】With the increase of stress,the germination ability of cotton seeds was significantly inhibited,the average seed germination rate decreased with the increase of the temperature,and other indexes of germination were significantly higher with the increase of the temperature. The cold resistant germination ability of cotton seeds was positively correlated with the tested germination index. At the same low temperature,two kinds of subordinate function method showed a good agreement on the seed germination ability at low temperature,but the germination rate of cotton seed under different low temperature was different. The seed germination of Zhongmiansuo No. 36 and Xinluzao No. 46 had a high chilling-tolerance at 15℃,and at 25℃,those with high chilling tolerance were Xinluzao No. 25,Xinluzao No. 42,Xinluzao No. 36,Xinluzhong No. 26,Zhongmiansuo No. 36,Xinluzao No. 41 and Xinluzao No. 35. Except for the average germination speed,the relationship among others germination parameters and seed germination ability was significantly correlated. The identification model for cold resistant cotton seed germination under low temperature was established by stepwise regression method： Y = 0. 01 ＋0. 022＊GI（ germination index）（ R2= 0. 998） at 15℃; Y =-0. 046 ＋ 0. 002＊GR（ germination rate） ＋0. 005＊SGC（ Seed germination coefficient）（ R2= 0. 992） at 12℃. 【Conclusion】The seed of Zhongmiansuo NO. 36 and Xinluzao NO. 46 had a high chilling tolerance at the seed germination stage. The germination index of fuzzy membership function method can be effectively used for the identification and evaluation of cold tolerance based on cotton seed germination.