Devolopment Of Genetic Male Sterile Lines Of Chinese Cabbage With Orange Heading Trait And Clubroot Resistance

Orange head Chinese cabbages are known for bright color, rich nutrition and high health value.The clubroot disease in crucifers, caused by Plasmodiophora brassicae, has brought great damagein cruciferous vegetable production, and resulted in Chinese cabbage suffer most seriously forlonger growing period. In the paper utilized AB lines type I of common head Chinese cabbage withhomozygous resistance gene and orange head inbred lines, the genetic male sterile lines of orangeleaf head Chinese cabbage with anti-clubroot were bred. And cotyledon color of orange headChinese cabbages was studied. The main results were described as follows:1. In order to accelerate the process of transformation, Blade traits and economic traitsof different orange head materials were surveyed in rosette period and in heading period. Blade traits of No.124and125were consistent with CR9112A, and head color of No.123and125were best. So No.123was selected as orange head parent, CR9112A as resistant sourceand sterile source. On the other hand, identification results of fertility and resistance of No.125showed that its fertile genotype was msms, and resistant genotype was rr, which was flu on clubroot.2. On the basis of proving resistance and fertility genotypic identification of orange headChinese cabbage, the model of transfer the genetic male sterile line of anti-clubroot orange headChinese cabbage were proposed. In the light of the model, the new male sterile lines weretransformed obtained by crossing, selfing, sib-mating and testing. During the course oftransformation, resistance was first identified, second head color, third characters, last fertility. It wassolved how to gain successful genetic male sterile lines when three traits need to be transfer.3. The orange head Chinese cabbage self-line (LH) and the common head Chinese cabbage(9112) self-line were parents, and by cross, reciprocal cross, selfing and back-cross, F1, F1′, F2andBC1F1were gotten. The cotyledon and head of F1and F1′were both yellow, the separation ratio ofF2and BC1F1cotyledon color were3:1and1:1(yellow to orange)respectively, which showed thatcotyledon color of orange leaf head was controlled by a pair of recessive alleles. And the inheritanceof cotyledon color, flower color and leaf head color belongs to pleiotropism. Under the dark or weaklight treatment, seed leaves of orange leaf head Chinese cabbage showed orange after they wereexposed in the sun for about two hours. Under the low temperature (0-3℃)and dark conditions,orange seed leaves of orange leaf head Chinese cabbage were observed more clearly, which were not affected by time of pregermination(24h or48h). So Cotyledon color of orange leaf head Chinesecabbage can be used as an ideal morphological character to apply to the breeding of orange headChinese cabbage.4. Orange head seedlings, which were gotten by orange as morphological marker inBC1F1, went through resistant identification. After resistant orange head seedlings of BC1F1crossed, there were fertile plants of AB lines type I with orange head and homozygosisresistant genes in BC1F2. The fertile plants went on in self. Passing resistant and fertileidentification of BC1F3, AB lines type I with orange head and homozygosis resistance werecome when the sterile plants in BC1F3sib-mated the fertile plants that should be tested.Cotyledon method screening orange head were finished before resistant identification.Therefore plants of resistant test were less, so did that of character traits.5. Making use of AB lines type I fertile plants with common head and homozygosisresistance and orange head self-line, new genetic male sterile lines were transformed. Becauseresistance and orange head of F2were homozygous in step by F1sib-mating, male sterile lineswere obtained in the fourth generation. When orange head plants with anti-cluroot were screened inthe second generation, orange heads were picked out at the stage of surveying economic traits byhead color method, and at the blooming stage by flower color method, and at the seedling stage bycotyledon color method. Identification groups of cotyledon color method were the smallest insurveying resistance and economic traits in BC1F1or F2.