扁穗雀麦种子发育过程中生理生化研究

Changes of Physiological and Biochemical Characteristics During the Seed Development of Bromus cartharticus

为探究扁穗雀麦种子发育过程中生理特性和变化规律,以江夏和黔南两个常见品种为研究对象,对花后不同时期的种子含水量、营养物质、酶活性和ATP进行测定。结果发现,江夏和黔南种子含水量除花后第42d有所上升外,其余时间均表现为逐渐下降,并以花后第32~36d下降幅度最大,分别为每天4.66%和4.84%。可溶性糖含量变化在品种间差异较大,江夏基本表现为先升后降,其中花后第19~32d显著高于其它时期(P<0.05);黔南则持续下降,但于花后第32d含量趋于稳定。淀粉含量变化品种间虽有差异,但均在花后第25d含量最高,分别为433.86 mg/g和412.95mg/g;在花后第36d含量最低。随着种子的发育,两品种脱氢酶活性变化规律基本一致,表现为先增后减趋势,并于花后第32d达最高值0.598μg/min/g和0.471μg/min/g,与其它各阶段差异显著(P<0.05)。ATP含量江夏表现为双峰曲线,分别在花后第19d和第36d较高,而黔南呈单峰变化,在花后第32d高达4.19μmol/g。对扁穗雀麦江夏和黔南各生理指标进行相关性分析发现,除黔南可溶性糖含量与种子含水量极显著相关外(P<0.01),江夏各指标间及黔南的其它指标间差异均不显著。综合考虑,两品种适宜在种子含水量分别为27~45%和30~49%时收获。

To explore the physiological and biochemical characteristics of Bromus cartharticus,Jiangxia and Qiannan two varieties were studied during the seed development.The moisture content,nutrients,enzyme activities and ATP of seed were measured after anthesis.The results showed that the seed moisture content of two varieties decreased gradually except for 42 d after anthesis.The greatest decrease of the seed moisture content was from 32 to 36 d,4.66%and 4.84%per day,respectively.The change of soluble sugar content was significantly different between two varieties.The soluble sugar content of Jiangxia was significantly higher from 19-32 d after flowering than other periods(P<0.05).The soluble sugar content of Qiannan continually decreased after anthesis and attended to become stabilized at 32 d.The highest starch content of Jiangxia and Qiannan were 433.86 mg/g and 412.95 mg/g at 25 d after anthesis,and the lowest starch content occurred at 36 d.With the development of seeds,the dehydrogenase activity of two varieties showed the similar trend,which increased firstly and then decreased.The highest values of the dehydrogenase activity were 0.598μg/min/g and 0.471μg/min/g,respectively,at 32 d,which showed significant differences compared with other periods(P<0.05).The ATP content of Jiangxia showed a bimodal curve,which was higher at 19 d and 36 d after anthesis.The ATP content of Qiannan showed a single peak change and had the highest value at 32 d.The correlation analysis of physiological indexes showed that there was a significant correlation between soluble sugar content and water content of Qiannan(P<0.01),but there was no significant difference among other indexes of Jiangxia and Qiannan.In conclusion,the optimal harvest time was that moisture contents reached to 26~45%and 32~49%respectively.