Effects of Lateness Gene on Yield and Related Traits in Indica Rice
Various genes which control or affect heading time have been found in rice. Out of them, Se1 and E1 loci play important roles in determining heading time by controlling photosensitivity. An isogenic-line pair of late and early lines were developed from progenies of the F1 from Suweon 258 × 36U. A lateness gene tentatively designated as “Ex” was found to control the difference in heading time between the early and late lines mentioned above. The present study was conducted to examine the effect of Ex on yield and related traits. Indica-type variety Suweon 258 was crossed with 36U, which is an Ur1 (Undulate rachis-1) isogenic line of IR36. In the F2 population, comparatively early-heading, late-heading and intermediate-heading plants were segregated. Segregation similar to that by the three types of heading was observed in the F3 and later generations. A late-heading plant and an early-heading plant were selected in the F8 population from an intermediate-heading F7 plant, for developing L and E of the isogenic-line pair, respectively. Experiments for L and E were conducted by randomized block design with three replications. Transplanting was conducted on May 3 at a planting distance of 30 cm × 15 cm with two seedlings per hill to an experimental field of the Faculty of Agriculture, Kochi University. Chemical fertilizers containing N, P2O5 and K2O were applied at the nitrogen levels of 4 g/m2, 9 g/m2 and 18 g/m2 in total being denoted by "N4", "N9" and "N18", respectively. Yield, yield components and other traits were measured. Ex delayed 80%-heading by 17 or 18 days in L as compared with E. In total brown rice yield (g/m2), L was 635, 606 and 590, and E was 577, 548 and 501, respectively, at N18, N9 and N4, indicating that Ex increased this trait by 10% to 18%. Ex increased yield-1.5 mm sieve (g/m2) b 9% to 15% at the three fertilizer levels. Ex increased the spikelet number per panicle by 16% to 22%. As a result, the spikelet number per m2 was increased by 11% to 18% at the three fertilizer levels. Ex decreased 1000-grain weight (g) by 2 to 4%. L was not significantly different from E in ripened-grain percentage, fertilized-spikelet percentage and percentage of ripened grains to fertilized spikelets. Hence, it is inferred that Ex increased yield by increasing spikelet number per panicle. Hence, Ex could be utilized to develop high yielding varieties for warmer districts.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1314455Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 618
 Chandraratna, M. F. “A gene for photoperiod sensitivity in rice linked with apiculus color,” Nature, Vol. 171, pp. 1162-1163, 1953.
 Chang, T. T., B. S. Vergara and C. C. Li “Component analysis of duration from seeding to heading in rice by the basic vegetative phase and photoperiod sensitive phase,” Euphytica, Vol. 18, pp. 79-91, 1969.
 Dahal, A., S. Hori, H. Nakazawa, K. Onishi, T. Kawano, and M. Murai “Inhibiting gene for a late-heading gene responsible for photoperiod sensitivity in rice (Oryza sativa),” International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering, Vol. 7 (7), pp. 1302-1306, 2013.
 Saito H., Y. Okumoto, Y. Yoshitake, H. Inoue, Q. Yuan, M. Teraishi, T. Tsukiyama, H. Nishida, T. Tanisaka “Complete loss of photoperiodic response in the rice mutant line X61 is caused by deficiency of phytochrome cromophore biosynthesis gene,” Theor Appl Genet, Vol. 122, pp. 109-118, 2011.
 Ichitani, K., Y. Okumoto and T. Tanisaka “Genetic analysis of the rice cultivar Kasalath with special reference to two photoperiod sensitivity loci, E1 and Se1,” Breed. Sci., Vol. 48, pp. 51-57, 1998b.
 IRRI “Parentage of IRRI crosses IR1 – IR30,000,” The International Rice Research Institute, PO Box 933, Manila, Phillipines, 1980.
 Kawano, K. and A. Tanaka “Growth duration in relation to yield and nitrogen response in the rice plant,” Japan. J. Breed., Vol. 18, pp. 46-52, 1968.
 Khush, G. S. and Virk P. S. “IR varieties and their impact. Los Banos (Philippines)”: International Rice Research Institute, p. 163, 2005.
 Masayuki Murai, Katsuya Nakamura, Miko Saito, Atsushi Nagayama and Kazuo Ise “Yield-increasing Effect of a Major Gene, Ur1 (Undulate rachis -1) on Different Genetic Background in Rice” Breed. Sci., Vol. 55, pp. 279-285, 2005.
 Ministry of Agriculture, Forestry and Fisheries “Characterization of rice and wheat varieties,” Agricultural Production Bureau, p. 136, 153, 1997 (in Japanese).
 Okumoto, Y., Ichitani K, Inoue H, Tanisaka T. “Photoperiod insensitivity gene essential to the varieties grown in the northern limit region of paddy rice (Oryza sativa L.),” Euphytica, Vol. 92, pp. 63-66, 1996.
 Okumoto, Y., T. Tanisaka and H. Yamagata “A new tester line for analyzing heading time genes in rice,” Rice Genet. Newsl., Vol. 8, pp. 129-131, 1991.
 Poonyarit, M., D. J. Mackill and B. S. Vergara “Genetics of photoperiod sensitivity and critical day length in rice,” Crop Sci., Vol. 29, pp. 647-652, 1989.
 Tokio Imbe “Rice breeding in the tropical Asia - one of the aspects-,” Gamma Field Symposia, No. 41, Institute of Radiation Breeding, NIAR, MAFF, Japan, 2002.
 Trieu, T. A., S. Malangen, S. Dozaki, T. Akaoka, Y. Takemura, M. Urabe and M. Murai “Single-genic segregation in heading date, observed in a progeny (F8 generation) of the cross between twoindica-type varieties in rice,” Shikoku J. Crop Sci., Vol. 47, pp. 44-45, 2010.
 Wada G., and Cruz, PCS. “Varietal difference in nitrogen response of rice plant with special reference to growth duration,” Jap. J. Crop Sci., Vol. 58, pp.732-739, 1989.
 Xue W., Y. Xing, X. Weng, Y. Zhao, W. Tang, L. Wang, H. Zhou, S. Yu, C. Xu, X. Li & Q. Zhang “Natural variation in Ghd7 is an important regulator of heading date and yield potential in rice,” Nature, Vol. 40 (6), pp. 761-767,2008.
 Yokoo, M. and F. Kikuchi “Multiple allelism of the locus controlling heading time of rice, detected using close linkage with blast-resistance,” Jpn. J. Breed., Vol. 21, pp. 123-130, 1977.
 Yokoo, M. and F. Kikuchi “Monogenic control of basic vegetative phase and photoperiod-sensitive phase in rice,” Japan. J. Breed., Vol. 32, pp. 1-8, 1982 (in Japanese with English summary).
 Yokoo, M. and H. Fujimaki “Tight linkage of blast resistance with late maturity observed in different Indica varieties of rice,” Jpn. J. Breed., Vol. 21, pp. 35-59, 1971.
 Yokoo, M., F. Kikuchi, A. Nakane and H. Fujimaki “Genetical analysis of heading time by aid of close linkage with blast resistance in rice,” Bull. Natl. Inst. Agric. Sci., Vol. D31, pp. 95-126, 1980 (in Japanese with English summary).
 Komatsu Y., T. Kon, K. Matuso, N. Katayama and T. Kataoka, “Varietal characters of high-yielding foreign rice”, Bull. Shikoku Agic. Exp. Stn. No. 43, pp. 1-37, 1984 (in Japanese with English summary).