The Molecular Studies On The Ds Inserted Rice Mutant And Physiological Analysis Of Non Ds Inserted Rice Mutant

A series of mutants were screened from Ds-inserted population, including late head, albino, dwarf etc. Among these, two mutants were physiological and genetically investigated, and whether the mutants were cosegregative with Ds or not was also analyzed.A dwarf and delay head mutant was controlled by a single recessive gene. The head date was not affected by photoperiod. By application 0.1% Basta to young leaves of each T₁ plant, it was found that the ratio of Basta resistant to sensitive plants was 3:1 indicating that Ds was single insertion in this line. Moreover all plants with mutant phenotype were Basta resistant suggesting that Ds was cosegregated with the mutant. The fact that selected 12 T₁ plants with mutant phenotype were homozygous for Ds and 5 T₁ plants with normal phenotype were heterozygous for Ds also supported above analysis. The results of PCR and Southern blot further confirmed that mutant phenotype cosegregated with Ds. By using inverse PCR (IPCR), the DNA fragment flanking the right border of Ds (T-DNA) was amplification. The results of sequence and Blast comparison demonstrated that Ds inserted in protein coding DNA region in chromosome 1.A lazy rice was also screened in Ds inserted population. It was controlled by a single recessive gene, and Ds (T-DNA) in this line was also single insert. The lazy rice was insensitive to gravtropic stimulus, exogenous auxin could not restore the gravitropic response, and the amolyplast in lazy rice was not defective. The gravitropic responses of roots and coleoptiles were also investigated; it was found that they exhibited normal gravitropic response. Genetic analysis demonstrated that it was not caused by Ds-insert although Ds was single insertion.