Preliminary Research Of Creep Mutant And Analysis Of Genotypes Of Rice Variety With Tolerance To Pi Deficiency

The tiller angle of rice was an important agronomic trait that contributed to grain production ,and had long attracted attentions of breeders for achieving ideal plant architecture to improve grain yield . Studies were mainly concentrated on its phenotypic description and physiological experiments,and the corresponding gene(s) had not been identified,leading to the poor understanding on molecular mechanisms in crops. Only the certain mutants in crops had been reported just as the lazy in maize and rice .In this study ,genetic analysis and preliminary mapping of creep mutant gene were conducted. The F1 and F2 population derived from a combination of P98 ,a line with lazy,and 81399 ,a restorer line with normal tiller angle. Bulked segregation ananlysis (BSA) and simple sequence repeat (SSR) markers were available for the first mapping . The main results were as following : (1) For F1 hybrid plants,the tiller angle is normal as 81399. And the segregation ratio of lazy plants to the normal tiller angle plants was 1:3 in the F2 population ,which indicated that the mutant trait was controlled by a recessive gene. (2) The SSR marker RM5903 was found to be linked with the creep mutant locus, their genetic distance was 25.2centimorgan . (3) The DNA sequence of La mutant and creep mutant were detected, the results indicated the two mutants were different ,and also , the creep trait of P98 was controlled by a new gene .On the other hand , to study the genes controlled the Pi [0]deficiency trait in rice , 698 SSR markers were screened between the two varieties Chenghui 448 and GP226 , a neargenic line of Chenghui 448. There was polymorphism with two SSR markers between the two parents ,which were located on chromosome 3 and on chromosome 10 , respectively.