Study On The Change Of Soluble Sugar And Differences Of Isoenzyme Between Pennisetum Hybrid And Its Female Parent In Seeds And Seedling

Pennisetum hybrid, Pennisetum americanum×P . Purpureum , belonging to the Gramineae Family and Pennisetum, is a perennial herbage with high production, strong stress tolerance, good palatability and high nutrient value, and widely planted in south China. Growing conditions from seed germination to seedling stage impacted late growth directly. Seed quality and varietal identification of hybrid and female parent in early period, are the key for seed production and widely planted.This paper studied the seed germination performance of pennisetum hybrid and its female parent in different treatments, discussed the seed germination physiology which set soluble sugar as an important physiological trait. Revealed the effect and change rule of soluble sugar during physiological regulation. Moreover, we aimed to explore and solve the problem about identification of hybrid and female parent in early period by studying the difference of isoenzyme bands.The results showed the optimal germination temperature was 25～30℃for hybrid, and 25～35℃for female parent, 30℃was the best. The soluble sugar content of seeds decreased rapidly with the increase of storage time, the decrease of nutritious matters impacted seed germination. Cold acclimation in 5℃for 3 days, then germinated in 15℃, germination rate increased 17.0% and 76.9%, and effect was obvious to female parent. The soluble sugar content decreased rapidly on the imbibition and germination, then increased rapidly by decomposition of seed and later decreased to provide nutrition for rapid growth of seedling and radicle.Cold and drought stress could increase the soluble sugar content, which related with degree and time of stress. The soluble sugar content of pennisetum hybrid was higher significantly than female parent (P<0.01) by cold stress in 8℃. But in serious drought treatment, the soluble sugar content of female parent was higher, and the time was later when seedling withered and died.Nine bands were found in POD isoenzyme electrophoresis in seedling stage, which could be divided into slow area,middle area and fast area. Bands in slow area stained stronger, slow in mobility. Middle area bands were tailing and difficult to apart. Bands in fast area were abundent but weak stained, and some of them were difficult to identificate. Female parent included band Rf 0.023, pennisetum hybrid missed. By contrast with the effects of electrophoresis about SOD,EST and POD isoenzyme, only POD isoenzyme included abundent bands, the bands of single plumule were clear and could be identificated easily. Pennisetum hybrid included band Rf 0.143 which female parent missed. Female parent included band Rf 0.295, which pennisetum hybrid missed. This could be used to identificate pennisetum hybrid and female parent in early period.