1College of Horticulture，Hunan Agricultural University，Changsha 410128，Hunan，China；2Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding，Ministry of Education，Changsha 410128，Hunan，China；3Institute of Vegetables，Hunan Academy of Agricultural Sciences，Changsha 410125，Hunan，China
Abstract：In order to explore new pepper semi-dwarf germplasm that could be applied to production，pepper inbred line ‘6421’ and its EMS induced semi-dwarf mutant ‘E483’ were used as test materials；conducted analysis on phenotype，biomass，photosynthetic characteristics，physiological indexes and inheritance of mutant；and confirmed its semi-dwarf mutation characteristics．The results showed that the internode distance in plant of mutant ‘E483’ was shortened，and plant heights in each development period were about half of ‘6421’．The leaves became smaller，and leaf area was extremely significantly lower than‘6421’．The leaves were dark green in color．Flowers became smaller．The lengths of petal，anther，stigma and silk were all extremely significantly inferior to‘ 6421’．The fruits became shorten and widen．The single fresh fruit weight and single plant fruit setting number were extremely significantly lower than‘ 6421’．The root length became shorter，and root depth，width，expansion area were all extremely significantly below‘6421’．The root vigor extremely significantly exceeded‘ 6421’．The fresh and dry seedling weights were all extremely significantly lower than ‘6421’．Fresh weight root-shoot ratio was significantly lower than‘6421’．The contents of chlorophyll and carotenoids，and photosynthetic parameters Pn，Gs，Ci and Tr in leaves were extremely significantly higher than‘ 6421’．The MDA content was extremely significantly lower than‘ 6421’．The contents of soluble sugar and proline were significantly or extremely significantly higher than‘6421’．The activities of SOD，POD，CAT，GR，and SA value were extremely significantly higher than‘6421’．The results of genetic analysis showed that semi-dwarf mutant character was recessive monogenic inheritance．
