Determination Of S-Genotypes Of Pear Dwarfing Mutants And The Cloning Of Genes Encoding DELLA Protein

This experiment with estimation of chance seedling dwarf mutant of Yanbian xiaoxiangshuili (Pyrus.ussuriensis Maxim) and other sixteen Yanbian pear cultivars, pear rootstocks as the materials, Using a pair of primers specific to pear S-RNases, PCR amplification from their genomic DNAs. Then the PCR products were extracted, cloned and sequenced. The amplified fragments were assigned to their respective S-RNases by blast analysis, conjecture the parents of pear dwarf mutant; RT-PCR and Rapid Amplification of cDNA Ends(RACE) technique was used to obtain a full length cDNA of the gene encoding DELLA protein. the result are as follows:The S-genotypes of the pear dwarf mutant and other sixteen Yanbian pear cultivars, pear rootstocks were identified as follows: 'dwarf mutant '(S1S17); 'Pingguoli' (S1S17); 'Yanguangli'(S1S17);'Dongning5haodali'(S1S17);'Pingboxiang'(S1S8m);'Zaosu'(S1Sd);'Yanbianxiehuatian '(S17S31);'Jianbali'(S12S30);'Yanbianmingyueli'(S3Se);'Xiaoxiangshuiyabian'(SeSx);'Chaoxianyangli'(SeS x);'Mishirazu'(S5Sx);'Shanli'(S12Sx);'S2'(S1S17);'S5'(S17S31);'S7'(S1S17);'PDR54 (S4S8S17).The S8m of 'Pingboxiang' is new gene,'PDR54'was triploid plant.A gene encoding DELLA protein was isolated from pear dwarf mutant by RACE technique,named PuRGL. It is 1743 bp, coding a polypeptide of 580 amino acids. Homology analysis showed that the deduced PuRGL protein was highly homologous o the MdRGL2a,MhGAI,RcGAI,PtRGAS,AtRGL2, the identity respectively is 98%,98%,82%,81%,77%.Two genes encoding DELLA protein was isolated from Pingguoli by RACE technique.The one gene is long 1755 bp, coding a polypeptide of 584 amino acids,named PaRGL1. Homology analysis showed that the deduced PaRGL1 protein was highly homologous to the MdRGL2b,MhGAI,RcGAI,PtGAS,AtRGL2, the identity respectively is 99%,93%,83%,82%,78%,78%;Another gene is long 1743 bp, coding a polypeptide of 580 amino acids,named PaRGL2. Homology analysis showed that the deduced PaRGL2 protein was highly homologous to the MdRGL2α,MhGAI,RcGAI,PtGRAS,AtRGL2, the identity respectively is 98%,98%,82%,81%,77%.