A Study On Genotypic Differences Of Ramie In Potassium Nutrition And Its Mechanism

Potassium supply in soil is deficiency in China, and it has not plenty of K fertilizer resource. A lot of foreign exchanges have been spent for importing K fertilizer,but it still couldn't meet the demand of agricultural production. It is imperative to explore a new way for alleviating K resource deficiency. One of the most economic and effective ways is to screen and develop new varieties of high K efficiency and tolerant to low-K.Ramie is a native crop in China, and its fiber is an important export product earning foreign exchanges. It has been planted for thoushands of years in China. Because the ecological environment of mineral nutrition of ramie is relatively complicated,it is possible to develop different mineral nutrition genotypes from it. If the characters of K nutrition and its mechanism are studied and clarified among various genotypes of ramie,it will be very favourable to screen and utilizate ramie genotypic resource of high K efficiency and tolerant to low-K,and to improve fiber output, fiber quality and the efficiency of K fertilizer application.This study has its theoretical and practical significance in the ramie production.The differences of biomass yield and K nutrition characters of ramie were studied for the first time by field microzone experiment, soil pot culture, solution culture and screening experiment. The mechanism of genotypic differences of K nutrition were also studied by investigating root morphology,physiology and K uptake kinetics. The main results are as follows:(l)The biomass of stems and leaves, absorption, accumulation, distribution and utilization of K were significantly different among various genotypes of ramie* and its utilization efficicency of K fertilizer is different too. Under low K condition of soil, the dry...