Identification Of Dwarf Mutants Of Common Wheat Variety Shannong 33 And Mapping Of Dwarf Gene JB016

13 dwarf mutants was identified from an NaN3-mutagenised population of common wheat variety Shannong 33.These dwarf mutants were used as material to investigate the agronomic traits,stem cell cytology,GA₃ response at seedling stage,endogenous hormone determination and dwarf gene detection.The reasons for dwarfing were analyzed from plant growth and development,stem anatomical characteristics,and the effects of hormones.The results showed that compared with the wild-type Shannong 33,the plant height of the dwarf mutants had a significant decrease,and the dwarfing of the plant height was not related to the number of internodes,which was mainly due to the shortening of the internode length,among which,the effect of peduncle and the first internode reducing plant height is obvious.Further microscopic observation of the cells showed that the reduction in plant height was caused by the shortening of the cell length and the decrease in the size of the cells,the shortening of the cell is the main factor.GA₃ reaction at the seedling stage showed that 13 dwarf mutants were GA-insensitive or weak-sensitive,indicating that there is a problem with the GA transduction pathway,the mutation site may be in the GA transduction pathway.Endogenous hormone measurements showed that the content of endogenous GA₃ in 13 dwarfing materials increased compared with Shannong33,while the content of endogenous CTK decreased compared with Shannong33,suggesting that the accumulation of GA₃ and the decrease of CTK affected the growth and development of the plants.Dwarf gene detection revealed that 13 dwarf mutants and Shannong 33 all contained Rht-D1b gene with a wide range of applications.The decrease in plant height of dwarf materials indicated that it should contain other dwarfing genes.This study can provide a wealth of materials and resources for further research and utilization of wheat dwarf genes.A panicle enclosure and dwarf mutant JB016 identified from an EMS-mutagenised population of wheat variety Jinghua No.1.The phenotypic characteristics,physiological characteristics and genetic characteristic of the mutant were analyzed.The results showed that:The plant height of dwarf mutant was 60.22±2.6cm,which was 55.5%lower than that of the wild-type（112.7±2.15cm）.The dwarfing of plant height was mainly reflected in the shortening of the internode,among them,the stem reduction effect of peduncle is maximum（65%）;Stem cytological observations revealed that dwarfing of mutants was caused by shortened cell length and reduced size of cells,in which cells become small was the main factor;endogenous hormone detection revealed that compared with the wild type,the GA₃ and BR of the mutant were no significant difference,while CTK and IAA of the mutant had a significant increase over the wild type,with an extremely significant increase in endogenous CTK of the mutant.It is speculated that the CTK transport pathway inhibits or hinders,resulting in the mutation of the mutant.Genetic Analysis of Dwarf Mutant JB016 by constructed F₁ and F₂ populations of JB016×CS.It was found that the F₁ exhibited high stalk parenting traits,and the dwarf and panicle enclosure trait were linked and the Chi-square test separated ratio was 3:1,indicating that the dwarf panicle enclosure trait of the mutant were controlled by a pair of recessive gene;further use of BSA+660K gene chip to locate the gene on chromosome 1A,Then,using the MBSA validation and SSR marker screening,the dwarf panicle enclosure gene JB016 was preliminarily located on chromosome 1A,the genetic distance from the molecular marker cfa2135 was 8.6 cM.The study of dwarf mutant JB016enriched the wheat mutant library and laid the foundation for the fine mapping and cloning of the dwarf gene.