Indexes For Screening High Phosphorus Efficiency Germplasm And Characteristics Of Introgression Lines In Dianjingyou No.1

Phosphorus deficiency is one of the limiting factors to rice production. Screening and breedingvarieties with high phosphorus efficiency can solve the problem. In this study, excellent germplasmfrom home and abroad as donor parents, and Dianjingyou No.1in Yunnan plateau as recipient.Introgression lines were generated. Studying on appraisal indexes of high phosphorus efficiency andtheir phosphorus efficiency characteristics of introgression lines of Dianjingyou No.1were conductedby soil culture pot and field experiment in japonica rice area of plateau. Germplasms with highphosphorus efficiency suited low phosphorus soil were screened. The main researches and results are asfollows:1. The appraisal indexes of phosphorus efficiency were established. Pot culture and fieldexperiment were conducted for analysis characters of rice varieties with different phosphorus efficiencyduring whole growth duration at two levels of no using phosphate fertilizer and using phosphatefertilizer. Nine biological characters of9high phosphorus efficiency varieties and3low phosphorusefficiency varieties including tillering numbers, chlorophyll SPAD value during heading stage, paniclesper plant, plant height, panicle length, total grains per panicle, seed setting rate, panicle weights perplant and1000-grain weight were investigated. The coefficient of variation and the fitness percentage ofdiscriminated genotypes with different phosphorus efficiency(the identified number of phosphorusefficiency varieties/the total of phosphorus efficient varieties) were analyzed by relative values (no P/P).Great variation exists in the relative values of panicle weights per plant, tillering numbers, grain numberper panicle and effective panicle number per plant were12.31%,12.03%,11.84%,11.35%, respectively,which other traits were lower than9.00%. The fitness percentage of different phosphorus efficiencyvarieties in tillering number, panicle weights per plant,seed setting rate, panicles per plant were77.78%,77.78%,77.78%and66.67%, respectively. Other traits were less than45.00%. The results showed thattwo traits of tillering number and panicle weights per plant, and three traits of tillering number, paniclesper plant and panicle weights per plant could be used to distinguish different phosphorus efficiencygenotypes. The fitness percentage were100%, which could be used as indexes of screening germplasmswith high phosphorus efficiency by potted. In field, the coefficient variation of panicles per plant,tillering numbers, total grains per panicle and panicle weights were16.68%,15.00%,14.86%,14.81%,respectively. Which other traits were lower than9.20%. The fitness percentage of tillering numbers,panicles per plant, panicle weights per plant and total grains per panicle were85.71%,57.14%,42.86%,and42.86%, respectively. Other traits were lower than29.00%. Integrating analysis of the four traitsfound that the fitness percentage were100%, which showed that t four traits combination could be usedto distinguish different phosphorus efficiency varieties. They were ideal indexes to screen germplasmswith high phosphorus efficiency.2. High phosphorus efficiency germplasm were screened. Under available phosphorus13.30mg·kg-1of soil stress in the field,93introgression lines derived from Dianjingyou No.1and3breeding varietieswere screened preliminarily for high phosphorus efficiency under two level of no using phosphatefertilizer and using phosphate fertilizer in the field during2010growth season. Tillering numbers,panicles per plant, total grains per panicle and panicle weights per plant were used as indexes. Theresults showed that35high phosphorus efficiency germplasm,14low phosphorus efficiency germplasmand47intermedius types were selected. Then,35high phosphorus efficiency germplasm andDianjingyou No.1were screened repeatly in field during2011growth season. The results showed that21high phophorus efficiency germplasm,9low phophorus efficiency germplasm and6intermediustypes were selected. Moreover,12high phosphorus efficiency germplasm and Dianjingyou No.1wereselected in pot culture. Tillering numbers and panicle weights per plant were used as indexes. Theresults showed that there were7high phosphorus efficiency germplasm,3low phosphorus efficiencygermplasm and3intermedius types. Comprehensiving analysis of these results above, six germplasmwith high phosphorus efficiency were screened in total, which might be applied in future breeding andphysiological study of high phosphorus efficiency.