Variations Among Cultivars Of Zizania Latifolia In Nutrients Accumulation And Distribution And The Mechanisms

As feature vegetable originated from China, Zizania Latifolia Turcz. was only cultivated along Yangze River and fewer south areas, and consumed around the areas before 80S of twentieth century. After that time, the planting structure has been adjusted and the system of vegetable circulation reformed, so Zizania Latifolia Turcz.has been introduced to many areas around China. Owing to the change of ecological condition, the growth and development of Zizania Latifolia Turcz were altered, but the cultivation technology used in some areas is from the origin place. The yield, quality and harvest time changed, and so as to the failure of the cultivation. So, it is very important for the research of high quality and yield technology in Zizania Latifolia Turcz to study the growth and development, the rule of main nutrients accumulation and distribution in plants (including tillers) during the plumping of stem, and the symbiosis of Ustilago esculenta P. Henn. with different cultivars, with Zizania Latifolia Turcz.cultivars of different types as materials.With two typical cultivars of Ustilago esculenta P. Henn. as materials, the changes of nutrients accumulation and concentration in different parts of the plants, and the relevant physiological changes, were investigated during plumping of the stems. A field study was conducted on the adjusting of the nutrients accumulation and distribution. Biological characteristics of symbiotic Zizania Latifolia Turcz. were pre-studied in the cultivars.In this research, A systematic research was conducted on the rule of main components accumulation and transport and the differences among cultivars. The to nutrient accumulation and transform were compared between two cultivars. and within cultivars were investigated after many years' cultivation and cultivar selecting. Some field experiments were conducted according to the rule of nutrient accumulation and distribution in different parts of plant and tillers. The results are showed as follows:1. Tiller's accumulation of dry matter was lower before colonies occlude period, then increased distinctly after colonies occlude period. It was considered that nutrients were mainly used to form new tillers. Dry and fresh weight of gall increased rapidly in its swelling. Those of culm, leaf blade, leaf sheath decreased accordingly, and falls of culm weight was the most.Culm was considered as 'mid-pool' of nutrients accumulation and transportation. Before the gall expanding, the accumulation of total sugar, reducing sugar and starch increased continuously and the greatest amount of carbon assimilates were observed to be accumulated in the culm, as compared with that in other organs. When zizania gall began to expand, the carbohydrate in other organs stopped accumulating. Most carbohydrates stored in culm were remobilized. The culm serves as stored organs for remobilized assimilates to the growth of zizania gall. Starch is the main form for stored carbohydrate, and most of 14C assimilates was pre-fixed in culm before pregnant. The accumulated carbohydrate in upper leaf and sheath of plant was higher than that of its lower leaf and sheath. During the period of gall expanding, Most of prefixed-14C was remobilized into gall. The labeled assimilates fixed by leaves supplied not only for its straws but also for the other parts of the plant. There were obvious differences between cultivars in accumulation, content, etc.2. The contents of N, P, K in the up-ground parts descended in zizania latifolia during the whole growth period and it reached the highest value at the gall swelling stage. The contents of N,P descended continuously while that of K fall and it increased notably before expanding. The contents of N, P, K of the culm declined smoothly at the beginning stage and declined rapidly when the gall began to expand. After expanding, the contents of N, P, K in the culm increased. The contents of N, P, K in the gall rose at the earlier expanding stage and then it declined steadily. But the change of protein content wasn't marked. The protein con...