| At present, the annual tillage mode problem becomes more and more serious, food safety and environmental ecological safety contradictions increasingly prominent. On contrary, Perennial crops have so many advantages, such as highly soil and water conservation, highly water and fertilizer use efficiency, biodiversity protection and so on. Therefore, perennial crops are very important to solve the above problems. But perennial trait wasn't controlled by a single gene in the past studies, perennial researchers are eager to find a model crop to research the mechanism of perennial. In this research, I use tetraploid maize Twf9,3-6 as the female parent and hybrid with Zea perennis (9475), to configure Aw9 groups and DL groups. The field observation found that, in similar genetic background and the same ploidy, hybrid generation F1 separate from the annual and perennial. Therefore, I studied the differences between the parental and hybrid F1 (annual and perennial populations) in morphology, cytology and DNA levels by genomic in situ hybridization and AFLP technique. The main results were as follows:1. The investigation of F1 hybrids'annual and perennial traits showed that Aw9 (15 plants) were annual, but DL (30 plants) were separated in annual plants and perennial plants,24 plants were perennial,6 plants were annual, so the segregation ratio was 4:1.2. The cytological identification of 3-6 and F1 showed that:3-6 plants with 40 chromosomes were come from maize, only 5 chromosomes have chromosome translocation which was between maize and Zea perennis, and the chromosome translocation phenomenon occurred in the No.3 and No.4 and No.7 and No.19 chromosomes. The chromosome numbers of Aw9 population was 38-43, among them 9 plants were 40 chromosomes and the proportion was 60%.40 chromosomes of Aw9 plants were composed by 20 maize chromosomes and 20 Zea perennis chromosomes, and there were not chromosome translocation phenomenon. The chromosome number of DL population was 40-42, and 29 plants were 40 chromosomes, which accounting for 96.7%; only DL-35 was 42 chromosomes. The chromosome of DL perennial plants were composed of 20 maize chromosomes and 20 Zea perennis chromosomes. There are 4 chromosome translocation, which were correspond to the translocation chromosomes of 3-6 in the third, fourth, seventh, nineteenth chromosome. The chromosome of DL annual plants,5 plants were 40 chromosomes and only one plant was 42 chromosomes. The DL annual plants(2n=40) were composed of 20 maize chromosomes and 20 Lea perennis chromosomes and the chromosome translocation phenomenon occurred in the No.7, No.10, No.12, No.19 chromosome. The DL annual plants(2n=42) were composed of 20 maize chromosomes and 22 Zea perennis chromosomes and only the No.19 chromosome appear chromosomal translocation.3.Using T-test to looking for some significant correlation phenotypic traits of perennial or annual. Aw9 was extremely significantly higher than annual DL in leaf width, but in leaf number and male main spike length Aw9 was significantly lower than annual DL. Between annual DL and perennial DL, only in leaf width and branch stem numbers, perennial DL was significantly higher than DL annuals, inferred perennial characteristics of DL may positively correlated with leaf width of main stem and branch stem numbers. In the first year, the plant height and leaf number of perennial DL were significantly higher than those in second years, and the tiller number of DL was significantly lower than perennial DL in second years.4. Using 64 pairs of AFLP primers to analysis annual plants (3-6, AW9, DL) and perennial plants (9475, DL perennial) genome, the results showed that:(1) In total,there were 5963 clear bands by 64 pairs of AFLP primers. There were 726 clear bands for parental 3-6 and 9475.457 specific bands for 3-6,317 specific bands for 9475. In the transmission rate of the parent specific bands and the total bands,9475 was higher than that of 3-6 in DL group.The result showed that the hybrid of 3-6 and 9475, in male and female combination, DL had the inclined to inherit the genetic material of 9475.(2) Between annual plants and perennial plants, there were 23 unique bands in annual plants, accounted for annual plants as 0.64%. There were 19 unique bands in perennial plant, accounted for perennial plants as 0.81%. It showed that the annual plant was similar to the perennial plant in main genetic material, and the separate of annual and perennial plant might be related to the genetic material of the 42 difference fragments. |
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