扁穗雀麦种子成熟过程生理响应及适宜收获期研究

Study on Physiological Response during Seed Maturation and Optimal Harvest Time of Bromus cartharticus

为探究扁穗雀麦种子成熟过程中的生理响应,明确适宜的收获条件和时间,以扁穗雀麦“江夏”和“黔南”为试验材料,对种子成熟过程中含水量、粒重、贮藏物质、酶活性和ATP进行研究。结果表明,随着种子的成熟,含水量呈持续下降趋势,但最大失水率在品种间有较大差异。“江夏”在花后第33~38天失水率最高,每天为4.94%,而“黔南”在花后第38~43天失水率最高,每天为6.45%。干重变化与含水量相反,“江夏”和“黔南”于花后第38天达生理成熟,分别为1.22 g和1.36 g;千粒重在花后第33天相对较高(11.25 g和14.13 g),后期粒重变化与品种熟性和落粒有关。可溶性糖在花后第13天内逐渐增加并达最大值(112.80 mg·g-1和106.76 mg·g-1),之后开始下降,并在花后第33~43天趋于稳定,淀粉含量变化基本表现为与之互补。ATP含量相对较高时期多为籽粒快速增加阶段;脱氢酶活性含量变化在种子成熟过程中不显著。综合考虑,“江夏”扁穗雀麦在花后第33天左右收获最好,“黔南”可推迟2~3 d。

In order to investigate the physiological response during Bromus cartharticus seed maturation and determine the suitable harvest conditions and time,the indexes including water content,grain weight,storage substance content,enzyme activities and ATP content of B.cartharticus varieties Jiangxia and Qiannan during seed maturation were studied.The results showed that with the maturity of seeds,water content continued to decrease,but the maximum water loss rate had a great difference among these varieties.The water loss rate of Jiangxia was the highest at 33 to 38 days with 4.94%decline per day,while that of Qiannan was the highest at 38 to 43 days with 6.45%decreasement per day.The change of dry weight content was opposite to water content,and the dry weight of Jiangxia and Qiannan reached physiological maturity on the 38 th day after flowering,which were 1.22 g and 1.36 g,respectively.In addition,the 1000-grain weight was relatively high(11.25 g and 14.13 g)on the 33 rd day after flowering,and the variation of grain weight was related to variety ripening and shattering trait.Soluble sugar content increased gradually and reached the maximum value(112.80 mg·g-1 and 106.76 mg·g-1 respectively)on the 13 th day after anthesis,then began to decrease,and tended to be stable on the 33 rd to 43 th day after flowering.And the change of starch content was basically complementary to soluble sugar content.The relatively high ATP content was mainly the rapid increase stage of grain,and the change of dehydrogenase activity was not significant during seed maturation.In conclusion,Jiangxia had the best harvest on the 33 rd day after flowering,while Qiannan had a delay of 2 to 3 days.