Yong-Gen LU, Guo-Chang WANG and Ren-HUA WANG
South China Agricultural University, Guangzhou, China
Genetic analysis of eight dwarf-statured cultivars of hsien (indica) rice in China (Table 1) was carried out in Guangzhou, China. The analysis was carried out to determine: 1) the mode of inheritance of dwarf-stature in different dwarfs; 2) allelic relationships among various dwarfs; 3) genetical classification of dwarfs.
The main results obtained are summarized as follows:
1. Tallness is incompletely dominant to the dwarfness of all dwarfs tested except Zhaiyeqing 8, Aizhongshuitiangu and Zhuchi.
2. The dwarfness of Aijiaonante, Aizizhan, Dijiaowujian (Dee-geo-woo-gen), Guangchang mutant, Zhaiyeqing 8 and Zhuchui is controlled by a major recessive gene. In addition, a set of modifiers with positive or negative effects is involved.
3. The dwarfness of both Aizhongshuitiangu and Fubaoai 21 is conditioned by minor genes and is under polygenic control.
4. Based on the results of the transgressive segregation, the strength of modifier effect might be Zhuchui>Guangchang mutant> Aizizhan> Aijiaonante> Fubaoai 21.
5. Based on the mode of inheritance of dwarfness and allelic relationships among the dwarfs, the existing dwarf-gene sources of hsien rice in China may be classified into two categories and four groups, as shown in Table 1.
Table 1. Classification of eight dwarf Hsien cultivars according to their genetic control ________________________________________________________________ Seasonal Modifier Cultivar Maturity Origin Dwarfing type gene genes ________________________________________________________________ Dijiaowujian Early cr. Late Taiwan DGWG Positive3 (Dee-geo- woo-gen) Zhuchui Late crop Medium Guangdong " " Aizizhan Early crop Late Guangxi " Negative4 Aijaonante Early crop Early Guangdong " " Guangchang mutant Early crop Medium GAAS1 " " Zhaiyeqing 8 Early crop Medium GAAS2 Independent Positive3 of DGWG Aizhongshui- tianku Late crop Late Indonesia minor genes Fubaoai 21 Late crop Medium Guangdong ________________________________________________________________1. Guangdong Academy of Agricultural Sciences, radiation-induced mutant from Guangchang 13.
2. Bred by GAAS with a dwarfing gene from Hualong-Shuitiangu, an Indonesian native cultivar.
3. Strongly positive and weakly negative effect in the mode of transgressive segregation.
4. Weakly positive and strongly negative effect in the mode of transgressive segregation.
Lu, Y. G., S. X. Zheng, Z. B. Li and R. H. Wang, 1979. A study on the phenotypic expression and genetic transmission of dwarf-gene sources of early hsien rice in China. Acta Genetica Sinica 6(3): 311-321.
Lu, Y. G., G. C. Wang and R. H. Wang, 1987. A study on phenotypic expression and genetic transmission of four dwarf-gene sources of hsien rice. Journal of South China Agricultural University (in press).