Study On The Difference In Phosphorus Ultilzation Efficincy Among Sugarcane Genotypes And Screening Phosphorus-Efficient Genotypes

Sugarcane(Saccharum sinensis Roxb.),as a typical tropical crop,is an important sugar-yield crop in China.Sugarcane is mainly planted in central and southern Guangxi,southwestern Yunnan and ethnic frontier regions of China.The development and growth of sugarcane demand for large amount of phosphorus.Besides,the soil of main sugarcane area in china is acidic soil which has Al-rich,Fe-rich and desilication.The phosphorus in the soils can easily be fixed to iron and aluminum oxide,which results to the lack of efficient-phosphorus and low phosphorus utilization rate.Therefore,low phosphorus deficiency is a main factor limiting the production of sugarcane.However,most sugarcane areas of southern China cover total-phosphorus-rich soils.Therefore,screening phosphorus-efficient sugarcane genotypes is a available measures to use soil phosphorus resources and improving sugarcane production efficacy.Therefore,120 genotypes of sugarcane,which are collected from different regions,were chused to study the differences in phospours-ultilization efficicy and screening high phosphorus-efficient genotpes.The main results as follows:1.Established evaluation and screening system,it is basic on the biomass of shoot,phosphorus accumulation and phosphorus utilization efficiency which evaluated and screened on different varieties of seedlings.2.The stress of phosphorus deficiency has a large impact on the biomass of shoot,the height of seedlings,phosphorus accumulation,phosphorus utilization efficiency and phosphorus content of leaves'(+5)in seedling stage of sugarcane.However,the biomass of shoot significantly related to phosphorus accumulation and phosphorus utilization efficiency,but it didn't show significant correlation with other traits.3.Under the stress of phosphorus deficiency,the chlorophyll content and the photosynthesis potential of high phosphorus efficiency genotypes was less affected.In contrast,under the stress of phosphorus deficiency,the chlorophyll content and the photosynthesis potential of low phosphorus efficiency genotypes have more impact.Therefore,the chlorophyll content and the photosynthetic fluorescence can be used as an auxiliary basis for evaluating the efficiency of phosphorus.4.On the basis of the biomass of shoot,phosphorus accumulation and phosphorus utilization efficiency in seedling stage of sugarcane was analyzed.The result showed that the varies of sugarcane can be divided into 5 categories.They are low-yield&low phosphorus efficiency,relatively low-yield&relatively low phosphorus efficiency,high-yield&low phosphorus efficiency,low-yield&high phosphorus efficiency and high-yield&high production efficiency.5.By cluster analysis and cane yield in mature stage of sugarcane,five sugarcane genotypes of high phosphorus efficient(FN91-21,MT01-77,GT97-69,YR06-8270,YR06-8362)and five sugarcane genotypes of low phosphorus efficient(Co285,TY14,YR05-782,YR05-784,YR06-2414)were selected.6.High phosphorus efficient genotypes mostly have excellent cultivated varieties of comprehensive genetic germplasm.Under the stress of phosphorus deficiency,the high phosphorus efficient genotypes have better developments,high tillering ability,more effective number of stems,high sugar,high yield,high photosynthetic potential and other characteristics.In contrast,the low phosphorus efficient genotypes have worse developments,poor tillering ability,less effective number of stems,low sugar,low yield,poor photosynthetic potential and other characteristics.Most of low phosphorus efficient genotypes are intermediate materials which are from Saccharum spontaneum or Saccharum arundinaceum breeding.High phosphorus efficient genotypes mostly are domestic varieties,and main low phosphorus efficiency genotypes are local or overseas.