不同抗寒性小麦品种生长点发育进程及生理指标差异分析

Difference Analysis of Development Process of Growing Point and Physiological Index in Wheats with Different Cold Resistance

为了解不同抗寒性小麦品种在寒地越冬期间分蘖节生长点发育进程及生理指标的差异,筛选适宜的抗寒指标,以抗寒性差异显著的3个小麦品种(中国春、济麦22和东农冬麦1号)为材料,在小麦生长期、驯化期和封冻期检测分蘖节生长点的分化进程、叶片的相对电导率和PSⅡ光化学效率(F_(v)/F_(m)),并测定叶片和分蘖节的丙二醛(MDA)含量以及抗氧化酶活性进行检测。结果表明,强抗寒性小麦品种东农冬麦1号的返青率较高,生长点分化较为缓慢,封冻期时生长点仍处于单棱期;而弱抗寒性小麦品种济麦22和不抗寒小麦品种中国春的生长点在2019年驯化期和2020年封冻期均已进入二棱期。2019年东农冬麦1号的叶片相对电导率以及2019和2020年叶片和分蘖节中MDA含量在封冻期均显著低于中国春和济麦22。此外,东农冬麦1号叶片和分蘖节的过氧化物酶(POD)和过氧化氢酶(CAT)活性在封冻期均显著高于中国春和济麦22,且其叶片的F_(v)/F_(m)显著高于中国春,但与济麦22无显著差异。总之,强抗寒性小麦品种生长点分化进程缓慢,封冻期时仍处于单棱期;且该时期叶片和分蘖节的MDA含量较低,POD和CAT活性较高,这些指标均可作为品种抗寒性的评价指标。

In order to understand the differences in the development process of tiller node growth point and physiological indexes of wheat varieties with different cold resistance during overwintering in cold region,and screen suitable cold resistance indexes.Three wheat varieties with different cold resistance(Chinese Spring,Jimai 22 and Dongnongdongmai 1)were used as materials.the differentiation process of tiller node growth point,the relative conductivity and PSⅡphotochemical efficiency(F_(v)/F_(m))of leaves,the malondialdehyde(MDA)content and the activities of antioxidant enzymes in leaves and tiller nodes of wheat was detected at growing stage,acclimatization stage and freezing stage in 2019 and 2020.The results showed that the overwinter survival rate of Dongnongdongmai 1,a strong cold-resistant wheat variety,was higher than Chinese Spring and Jimai 22,and the growth point differentiation of tiller node was relatively slow,its growth point was still in the single-edge period at freezing stage,while the weak cold resistance wheat variety Jimai 22 and the non-cold resistance wheat variety Chinese Spring had entered the two-edge period at acclimation stage in 2019 and freezing stage in 2020.The relative electrical conductivity in leaves of Dongnongdongmai 1 in 2019 and the MDA contents in leaves and tiller nodes in 2019 and 2020 were significantly lower than those of Chinese Spring and Jimai 22 at freezing stage.In addition,at freezing stage,the activities of POD and CAT in leaves and tiller nodes of Dongnongdongmai 1 were significantly higher than those of Chinese Spring and Jimai 22,and F_(v)/F_(m) in leaves of Dongnongdongmai 1 was significantly higher than that of Chinese Spring,but not significantly different from that of Jimai 22.In conclusion,the differentiation process of tiller growth point of strong cold-resistant wheat variety was slow,it was still in single-edge period at freezing stage.And MDA contents in leaves and tiller nodes was lower and the activities of POD and CAT were higher in this period,which could be used to evaluate the cold resistance of varieties.