Study On The Genetic Mechanism Of The Green Chinese Onion And The Impacts On The Quality

The early bolting of green Chinese onion (Allium fistulosum L.var. giganteam Makino) is an important factor that will influence the quality and yield.If the vegetable bolt early when it shouldn’t bolt when the vegetation has not yet fully grown,this phenomenon is called early bolting.Nowadays,the study about the mechanism of green Chinese onion bolting is only limited to the control methods,temperature and sowing date.In this experiment, we take the main cultivar of China-Zhangqiu green Chinese onion as a contrast to compare and identify the green Chinese onion varieties introduced from Japan.On this basis,we started with selecting bolting-resistant green Chinese onion sterile lines and maintainer lines, we studied the genetic mechanism of the green Chinese onion bolting as well as its influences in quality in order to provide theoretical basis for the selecting of different green Chinese onion especially the spring green Chinese onion under different stubbles.The main research results are as follows:1.In this study,by taking advantage of the sterile plant of Japanese Tiegan green Chinese onion,We selected the later bolting green Chinese onion sterile lines after test cross-backcross between the later bolting green Chinese onion varieties.We selected some later bolting,high yield and disease-resistant green Chinese onion New varieties by trial with combinations, thus provided a theoretical basis for the selecting of the spring onion.2.The amount of dry matter, soluble sugar, free amino acid and soluble solid of it was related with F1. So varieties of high content of dry matter, soluble sugar, free amino acid and soluble solid should be chosen as parent according to the goal of breeding. Heterosis of F1in the content of soluble sugar and soluble solid are significant compared with the parents. The expected varieties can be obtained by the way of heterosis breeding, especially when F1of high content of dry matter are taken consideration, it is easy to reach the goal if varieties of high content of dry matter are chosen as parents. This is a condition of breeding dehydrated spring onion.3.The main botany traits of green Chinese onion:The genetic relationship between leaf colour, Wax powder,leaf state and the leaf inclination. The basic rule of the leaf colour is: dark green×dark greenâ†'dark green;dark green×yellow-greenâ†'green;green×greenâ†'green;Wax powder×No wax powderâ†'F1is slight-Wax powder. Thus it was initially thought that leaf colour, Wax powder,leaf state and the leaf inclination are polygenetically control quantitative trait inheritance.4.Terminal buds of green Chinese onion turn into blossom buds from leafbuds after vernalization. Chinese onion is a kind of crop using chloroplast as receptor of low temperature to finish the process of vernalization. Varieties vary different in the aspect of flower bud differentiation. It is relative late for varieties of high winterness to bolting and blooming. So it should be considered again, when varieties own low winterness such as Zhangqiu green onion are used as materials to describe the size and thickness of plant finished vernalization.5.We must consider the storage-resistance besides the firmness of the scallion,lodging resistance, late bolting and high yield when selecting Bolting-resistant green Chinese onion varieties.Green Chinese onion is an important storage-supplying vegetable,so the storage-resistance is an important economic trait. The period of dormancy and the resistance to shrink and weight loss of the varieties with firm scallion,more and thick scales, high content of dry matter,soluble solid or sugar are longer and stronger.