Study On Inheritance And Utilization Of Tagates Erecta L.Male Sterile

In order to obtain new varieties of Tagetes erecta with intellectual property and high ornamental values, selective breeding and hybridization of Tagetes erecta have been conducted for 10 years successively. The main achievements are as follows:1. Male sterility of Tagetes erecta was discovered. 3 male sterility lines, 16 inbred lines and 6 optimal hybridization combinations (including 4 yellow combinations and 2 orange combinations) were obtained through intra-specific hybridization, and 2 optimal triploid hybridization combination (including 1 yellow type and 1 orange type) and 2 tetraploid Tagetes patula male parents (2n=4x=48).through interspecies hybridization.2. An important morphological marker about fertility (baldness type) was revealed by the study on the inheritance of male sterility and trait of parents and progenies derived from various cross combinations. It was identified that male sterility of Tagetes erecta was Nucleo-Cytoplasmic interaction type with the characteristics of environment insensitiveness and stable inheritance, and was qualitatively controlled by a recessive gene in nucleus. This result indicated that Tagetes erecta can be used in the cross breeding and hybrid production through three lines combination. In addition, inheritance of some flower characteristics, such as color, shape, height and flowering habits was also studed.3. The intermediate germplasm resources were established, including sibling hybridization germplasm resource, family germplasm resource and hybridization combination germplasm resource, etc.4. During the course of parent transmigration selection, the selection of same side cycling method for the first time was proved to be effective in parent breeding, and resulted in 6 optimal hybridization combinations. Comprehensive assessment demonstrated that 3 combinations were equal to or superior to overseas varieties.5. Inter-specific hybridization using male sterility line accomplished inter-specific intercross between Tagetes erecta and Tagetes patula with heterosis, and resulted in the yield of 2 triploid combinations ACHY021×PBHO026 and ACHY021×PBHO029. The plant shapes, root color and flower color were found to be similar to that of male parent, while leaf shape, leaf color and stem diameter close to that of female parent.6. 2 pairs of AFLP primers (M38/E53, M54/E44) were screened for distinguishing the male parents from female parent and progenies, and provides the scientific preparation for seed purity identification with AFLP technology. The analysis of parents using AFLP markers showed that there were more than 3.96% background differences in heredity between parents, which were much more than theoretical value. It indicated that there was a large conservative region near male sterile genes within Tagetes erecta genome, in whichgenes are closely linked to each other.In this present study, sterile hybrid progenies derived from optimal combinations guaranteed the protection of intellectual property. Meanwhile, inter and intra-specific hybridization using male sterility and molecular method for hybrid seed identification paved a new way for crossbreeding Tagetes erecta through male sterility.