Perakitan Padi Hibrida untuk Ketahanan terhadap Penyakit Hawar Daun Bakteri dan Mutu Gabah Baik.

Abstract

Breeding new rice variety does not always give adequate results, therefore it is necessary to develop methods for rice varieties breeding. Hybrid rice is an alternative to increase the productivity of irrigated rice in Indonesia. The new hybrid rice varieties are expected to have high yield potential, resistant to bacterial leaf blight, and have good rice quality. The use of other cytoplasmic CMS types (Gambiaca and Kalinga) aimed to anticipate genetic vulnerability and to increase the diversity of hybrid rice in Indonesia. The objectives of this study were (1) to determine the effect of female parents with different cytoplasmic sources on hybrid seed yield, (2) to select the parental lines of hybrid rice that had good combining ability and heterosis value, (3) to obtain information on the parents and hybrid rice which had BLB resistance and good grain quality, (4) to obtain hybrid rice with high yield, resistant to bacterial leaf blight and good grain quality. The research stages of hybrid rice breeding from three different cytoplasmic sources and had bacterial leaf blight resistant were: (1) Hybrid rice seed production for research materials and to evaluate the ability of seed production for each combination of hybrid rice. This experiment was carried out by crossing CMS parental with restorers to obtain F1 seeds. In the second experiment, there were two activities (2a) combining ability and heterosis value of hybrid rice, (2b) grain and rice quality evaluation. The third experiment was (3) the evaluation of hybrid rice for resistance to bacterial leaf blight. The research was conducted at the Indonesia Center fo Rice Research (ICRR), and in farmer field in Karawang, West Java from March 2021 to March 2022. The first stage is hybrid rice seed production of three cytoplasmic CMS types with 10 restorers to determine F1 seeds production ability which had a good hybrid rice combination. The highest hybrid rice seed yield was obtained from a combination of hybrid rice from female parents GMJ15A, and male parents PK90. The average F1 seed yield of female parental of the Gambiaca type GMJ15A line (1.03 ton ha-1 ) was equivalent to the WA type GMJ12A line (0.85 ton ha-1 ) and was significantly higher than the Kalinga type GMJ14A line (0.51 ton ha-1 ). The male parent (restorer) with the highest average seed yield was PK90 (1.36 ton ha-1 ). The number of grain contents per panicle and the outcrossing rate were positively correlated with the yield of hybrid rice seeds produced. The second experiment was a line x tester to study on the effect of female parents (CMS) and restorers to obtain new hybrid rice combinations with different cytoplasm. The objective of the study was to select the parental lines of hybrid rice that had good combining ability, heterosis and to obtain information on the parents and hybrid rice with high yields. The combined analysis of variance showed a significant effect between locations and hybrid rice on yield components. Results showed that the line parent GMJ14A, testers CRS1301 and CRS1310 had the best general combining ability (GCA). The combination of hybrid rice GMJ12A/R3, GMJ14A/CRS1308, GMJ15A/PK12 had the highest specific combining ability (SCA) and GMJ12A/R3 was significantly different at the 5% level. The combination of GMJ14A/CRSP323 hybrid rice had a grain yield of 8.33 ton ha-1 , and standard heterosis with HIPA21 (20.3%), Ciherang (28.4%), Inpari32 (23.5%). Parentals and hybrid rice which had the best general combining ability and spesific combining ablity need further yield tests. The third experiment was to obtain information on the grain quality, the parental quality and the good hybrid rice. There is a correlation between the characters of physical quality of grain, physical quality of rice, and quality of milled which is moderately strong (> 4%) to strong (< 7%). Based on the quality of milled rice, hybrid rice parents GMJ14A and CRS1308 had the highest yields of brown and milled rice. The parents of hybrid rice GMJ15A, R3, PK12, PK90, and hybrid rice combinations (GMJ12A/PK12, GMJ12A/PK90, GMJ12A/R32, GMJ14A/CRS1308, GMJ15A/R32, GMJ15A/PK88, GMJ15A/CRS1301) have premium quality standards with premium quality standards, head rice is more than 85% and brown rice is below 14.5%. The fourth experiment was the evaluation of resistance of hybrid rice to bacterial leaf blight. Resistance of hybrid rice to bacterial leaf blight disease is one alternative to increase rice yields. Evaluation of bacterial leaf blight disease resistance showed that the cytoplasmic CMS types WA, Kalinga and Gambiaca were resistant to bacterial leaf blight. Hybrid rice GMJ12A/PK88 has resistance to bacterial leaf blight pathotypes (III, IV, and VIII) generative phase. Genotype GMJ12A/PK12, GMJ12A/CRS1308, GMJ12A/CRS1310 and GMJ14A/R3 hybrids have pathotype resistance (III and VIII). The restorer CRS1301 and CRS1308 had pathotype III and VIII bacterial leaf blight resistance. The disease resistance of hybrid rice to bacterial leaf blight was strongly correlated with the resistance of the restorer parents having resistance to several pathotypes. Based on a series of experiments carried out in this study, CMS parental line GMJ15A type Gambiaca had an average seed yield equivalent to the GMJ12A type WA strain and significantly higher than the Kalinga type GMJ14A, all CMS types were resistant to bacterial leaf blight pathotypes III. GMJ14A parental line, testers CRS1301 and CRS1310 have the best GCA. The combination of hybrid rice GMJ12A/R3, GMJ14A/CRS1308, GMJ15A/PK12 had the highest SCA. Five hybrid rice combinations were obtained that had standard heterosis with HIPA21 > 5.6 %, Ciherang (>22.9%), and Inpari32 (>18%), grain quality and premium rice, resistant to bacterial leaf blight pathotype III. Four combinations of hybrid rice were obtained with heterosis standard with Ciherang > 10%, good grain quality and bacterial leaf blight resistance of more than 1 pathotype. Keyword: bacterial leaf blight resistance, CMS, combaining ability, grain quality and rice quality, heterosis, hybrid rice, restorer.