Rice Dominant Semi-dwarfing Genes Genetic And Molecular Markers,

This paper deals with semi-dwarfism dominant rice in three different aspects, such as genetics, molecular biology, physiology. The result followed:1. The semi-dwarfism of the mutant rice was controlled by a pair of dominant nuclear genes, not affected by cytoplasm. The semi-dwarf gene of dominant rice was nonallelic to the semi-dwarfism gene in KL908,sd-l gene in AKsdl and sd-s(t) in the XueHeAiZao. In the genetic background of CO78, an additive dominant gene was found in the semi-dwarfism rice .2.The discuss about the breeding value of semi-dwarfism dominant rice was conducted. Some good cultivars have been breeded .3.The influencing factors on RAPD were studied and experimental parameters were optimized.They were as follows:50ul system containing 40ng template, 0.8umol/L primer, 200umol/L dNTPs, 2.5Units TaqDNA polymerase, 2.0mmol/L MgCl2.The optimal amplification program was as follows: Imin at 94℃,followed by 94℃ for 30sec, 36℃ 30 sec, 72℃for 2min,for 40 cycles and final time of 72℃ for 7min.A high reproducible results were obtained with the optimized experiment conditions.4 A R. APD analysis was made between Y98149 and its near isogenic lines with 100 random primers.Five primers amplified the DNA polymorphic bands in the NILs. Further RAPD analysis of F2 population of 100 individuals using five primers showed AM04 and AY01 were closely linked to the new dwarfism gene with genetic distance 15.3 cM and 9.3cM.They located on the same side of the new semi-dwarfism gene.5. From environmental factor, sensitivity test to gibberellin were experimented among the semi-dwarfism dominance rice and other dwarfing breeds during their different period.As a consequence,a genetic law of semi-dwarfism dominant rice were studied deeply.An optimal RAPD system were founded.In addition, possible mechanism of dwarfing rice's origin were discussed.