IMPROVEMENT OF EARLY MATURITY IN RICE VARIETY BY MARKER ASSISTED BACKCROSS BREEDING OF Hd2 GENE

Abstract

Early-maturing and high-yielding rice variety is very useful for increasing rice production in Indonesia. The aim of this research was to develop new lines of Indonesian rice containing Hd2 gene using Code variety as a recipient parent and Nipponbare variety as a donor parent through targetted MAB approach using RM1362 and RM7601 in chromosom 7 for foreground selection. After two generations of backcrossing, the positive alleles of Hd2 gene from Nipponbare had successfully trans-ferred into Code. The plant number CdNp_29 in BC2F2 popula-tion had the highest genome recovery of 82.7%. The twelve BC2F3 plants were selected for self-pollination to generate BC2F4. These selected lines that carried the Hd2 gene were screened in the greenhouse for the evaluation of heading date and agronomic traits. All improved lines had Hd2 gene similar to the donor parent Nipponbare. The heading date of the breeding lines ranged from 73 to 89 days (Code 85 days) or fill the third criterion of rice maturity that is 103-104 days compared to Code of 116-119 days, whereas their agronomic performances were similar with that of Code. Application of MABc for im-proving rice early maturity has accelerated the development and selection in early generation of superior lines having genetic background of Code. It is expected that the newly developed lines of Code will be utilized to increase rice production in Indonesia.

Introgression of bacterial leaf blight (BLB) resistant gene, Xa7 into MARDI elite variety, MR219 by marker assisted backcrossing (MABC) approach

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Recent Advances in Rice Varietal Development for Durable Resistance to Biotic and Abiotic Stresses through Marker-Assisted Gene Pyramiding

“…Rice is subjected to Sustainability 2021, 13, 10806 2 of 25 an increasing number of abiotic and biotic stress combinations as a result of global warming and possible climatic change. This has a negative impact on rice growth and grain yield production [4][5][6][7][8][9][10][11]. Biotic stresses (pathogens, pests, weeds) and abiotic stresses (drought, submergence, salinity, heat, cold) negatively impact rice production worldwide.…”