Sh-2超甜玉米乳熟期籽粒大小糖分积累酶活性变化及其相关性分析

Changes of Kernel Size, Sugar Accumulation and Enzyme Activity in the Kernel of sh-2 Sweet Corn and Their Correlation Analysis During Milk Maturation

试验研究了夏季两个不同播期的sh-2超甜玉米乳熟期籽粒大小、糖分积累、酶活性的变化及其相关性．结果表明,由于籽粒乳熟后期脱水,籽粒长度、宽度、厚度、体积和可溶性总糖、果糖含量呈中间高,两头低的抛物线型;籽粒淀粉酶、过氧化物酶(POD)、超氧化物岐化酶(SOD)活性变化也均呈抛物线型;曲线符合方程=a+bx+cx2(y为籽粒大小、糖含量、酶活性,x为授粉后天数,a,b,c为参数)．相关分析表明,在播期一,α-淀粉酶、β- 淀粉酶、POD、SOD活性与籽粒长度、宽度、厚度、体积和可溶性总糖、果糖含量均无显著相关;在播期二,α-淀粉酶活性与籽粒长度、宽度、体积和可溶性总糖、果糖含量,SOD活性与籽粒长度、体积存在显著负相关．

The investigation on changes of kernel size, sugar accumulation and enzyme activity in the kernel of sh-2 sweet corn during milky maturity stage and their correlation analysis were conducted in two sowing stages. The results showed that during milky maturity stage changes of the length, width, thickness, volume of corn kernel and the content of the total soluble sugars and fruit sugar in the kernel showed parabola style. Also, the changes of activity of amylase, peroxidase （POD） and superoxide dismutase （SOD） were observed to present a parabola style. The curve could be simulated by regression equation y = a ＋ bx ＋ cx^2, where y was kernel size or sugar content or enzyme activity, x was day after pollination, a, b and c were parameters. The correlation analysis indicated that there were no significant correlations between theα-amylase, β-amylase, POD, SOD activity and the length, width, thickness, volume, total soluble sugars, fruit sugar contents of the kernels in sowing stage one. In sowing stage two, there were significant negative correlations between theα- amylase activity and the length, width, volume, total soluble sugars, fruit sugar contents of the kernels and between the SOD activity and the length, volume content of the kernels.