Investigation Agronomic Traits Of Mini-Core Collections And Identify The Mutants Of Differently Expressed Genes Under N,P Deficient Stress

Crop germplasm resources contain most of genetic informations of this species, it is an important material basis for seed-breeding and identifying unknown genes, so it is the precious wealth and it has become the strategic significance for a country.In this study, mini-core collection of213landraces is the main research material. Fourteen important agronomic traits of the collection were investigated and identified, including yield per plant,1000grains weight. The main results are as follows:1. The heading date of mini-core collection ranges from50～149d, coefficient of variation is18.09%, the materials which their heading date range from70～110d accounted for84.24%of total amount. The plan height of mini-core collection ranges from76.75～220.88cm, coefficient of variation is26.75%, there are more taller materials among the Indica and Aus type. The panicle length ranges from13.87～33.34cm, its coefficient of variation is14.98%, most materials’ panicle length ranged from17.00～29.00cm. The data of Japonica changes more apparently. Among the mini-core collection, there are33materials which have awn and the majority of them are Indica. Most materials’ awn length ranged from5.00～20.00mm. The yield per plant ranges from4.408～42.218g, its coefficient of variation is33.38%, and Indica yields is higher. The1000grains weight ranges from14.01～41.48g, its coefficient of variation is14.13%; the effective panicle per plant ranges from3～21, its coefficient of variation is32.92%; the seeding setting ratio ranges from35.94%～98.33%, its coefficient of variation is13.30%. Among this mini-core collection, there are very profound genetic diversity, which provides favourable materials for seed-breeding and identifying unknown genes.2. Correlation analysis demonstrated that yield traits affect and interact each other. There are very significant positive correlations between the yield per plant and the seeding setting ratio, the spikelets per panicle, the effective panicle per plant, the1000grains weight, the grain length.The correlations between the yield per plant and spikelets per panicle is most strong. Between yield per plant and plant height have remarkable negative relativity. There are also very significant positive correlations between spikelets per panicle and effective panicle per plant. Between the effective panicle per plant and the heading date, the plant height, the1000grains weight has remarkable negative relativity. There were very significant positive correlations between the1000grains weight and grain length, grain width, grain thick.3. Path analysis showed that the1000grains weight contributed most to the yield per plant, the seeding setting ratio ranked next and the effect of the spikelets per panicle on yield per plant is the least. The grain thick contributed most to the1000grains weight, and the grain length, the grain width ranked next. The function of grain length and the grain operator is similar.4. After identification, we got19dwarf materials which their plant height are less than90cm; and14multi-spike-type materials which their effective panicle per plant are more than15; and11large-grain-type materials which their1000grains weight are more than27g. We also got14materials with many excellent traits. It could be used in futher genetic research and seed-breeding in rice.With the continuous decrease of arable land, the food problems have become the political issue which is a matter of vital importance to a country.The huge amounts of chemical fertilizer are used in agricultural production, but excessive application of nitrogen, phosphorus not only reduces the nitrogen and phosphorus use efficiency, and declines the economic benefits, rice quality, but also caused great environmental threat. It is an ideal approach for enhancing nitrogen, phosphorus use efficiency and reducing environmental pollution to explore and utilize crop’s natural potential to screen efficient rice genotype. To do this, we must deeply understand the acquisition mechanism of nitrogen and phosphorus of rice, and discover new genes and regulatory elements for the continued perfection of nitrogen and phosphorus metabolic networks of rice. This study uses the technology of rice genome-wide cDNA microarray to analyse the gene expression profile under N, P deficient stress on different time. We get some differentially expressed genes (with ratio value≥2.0), then find and identify their mutant. Measure the total nitrogen、total phosphorus of straw and grain of heading and mature period to looking for the new genes or regulatory elements which may regulate the process of absorbing and transporting the nitrogen and phosphorus. The main results were as follows:1、We get166differentially expressed genes (with ratio value≥2.0), then we obtain131mutants after querying the information in rice mutant library. Plant them in the field, and do the positive identifying. 2、Plant the131homozygously inserted mutants material in Wuhan and Hainan in2011, and measuring the total nitrogen total phosphorus of straw and grain of heading and mature period. After analyzing data we select4genes as candidate, which have the effects in the process of absorbing and transporting the nitrogen.3、Plant the131homozygously inserted mutants material inWuhan and Hainan in2011, and measuring the total nitrogen、total phosphorus of straw and grain of heading and mature period. After analyzing data we select6genes as candidate, which have the effects in the process of absorbing and transporting the phosphorus.