| Sugarcane is the main economic crop for part areas in the south of China, quality and yield is affected by lack of nutrients, for screening sugarcane varieties of nutrients efficient utilization,we did cluster analysis for low resistance of nutrient index of the aboverground biomass, on the basis of weighted average of configuration value of main agronomic traits for different sugarcane varieties,and carried out preliminary the pot experiment for 98 sugarcane hybrid parent sugarcane by agronomic characters configuration value and method of resistance low nutrients index, screening typical sugarcane varieties, we carried out photosynthetic characteristics analysis of parts high nutrition efficient, middle nutrition efficient, low nutrition efficient varieties and verified the feasibility of the screening indices,at the same time, discusses the feasibility taking photosynthetic characteristics as index of screening high nutrients efficient varieties, The main results were outlined as follows:1. Nine varieties of high N-efficiency were selected, e.g. ROC22, guiO2/239, PR1059, and thirteen varieties of low N-efficiency, e.g. Badila, Heng xian fruit sugarcane, Luo gu sugarcane. Six varieties of high P-efficiency were selected, e.g. Ge shou mi94, Yue71/210, Ge shou mi 93, and thirteen varieties of low P-efficiency, e.g. Badila, ROC16, JA64/11. Eleven varieties of high K-efficiency were selected, e.g. Ge shou mi94, Yue71/210, Ge shou mi 93, and thirteen varieties of low K-efficiency, e.g. Heng xian fruit sugarcane, Badila, Gui04/2423. Three varieties of high nutrient-efficiency for three nutrients were Gui02/239, PR 1059 and Yue71/210, low nutrient-efficiency for three nutrients were Badila, Heng xian fruit sugarcane, Luogu, Gui60/289, Luzhe, Q124, POJ2725 and M64/11.2. Different conditions of low N, P and K inhibit the growth and development of sugarcane and reduce the plant height, stem diameter, leaf length and leaf area, root/shoot ratio, underground biomass, aboveground biomass, compared with low nutrients efficiency varieties, reduction of agronomic characters configuration value of high nutrients efficiency varieties lesser, the seven major agronomic characters shows obvious difference of varieties, agronomic characters of the biggest is aboveground biomass.3. According to reducing degree of photosynthetic characteristics in low nutrients, high nutrients efficiency varieties and low nutrients efficiency that we screened keep part consistent with varieties of high N-efficiency and low N-efficiency which screened in low resistance of nutrient index of the aboverground biomass, compared with sugarcane of low N- efficiency, high N-efficiency, has the higher intercellular CO2 concentration, photosynthetic rate, so we can use this two photosynthetic traits as screening reference index of high nitrogen efficiency of sugarcane seedling. |
