IJBSAT 2017 Volume 8 Issue 1

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Title:

Evaluation of some hybrid combinations for exploitation of two line system heterotic in Rice (Oryza sativa L.)

Authors & Affiliation:

Galal Bakr Anis, Ahmed Ibrahem El-Sherif, Hytham Freeg, Elsaed Farok Arafat

Rice Research and Training Center, Field Crops Research Institute, Agriculture Research Center, Egypt

gb_aness2010@yahoo.com, ahmedelshrif127@gmail.com, 3261673349@qq.com, ganis.rrtc@gmail.com

Abstract:

Photo-thermosensetive genic male sterile (PTGMS) lines of rice have tremendous potential in realizing further quantum yield and economical hybrid rice seed production cost. The study was conducted during two rice growing seasons of 2015 and 2016 at the Experimental Farm of the Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh, Egypt. Ten hybrid rice combinations derived from hybridization of one elite and adapted Japonica PTGMS line (PTGMS-38) and ten Indica, Japonica and Indica Japonica genotypes along with two check (Giza 178 and Giza 179) were used to analysis of genetic parameters and standard heterosis for 10 traits. Highly significant positive standard heterosis over the best local check varieties Giza 178 and Giza 179 for grain yield/plant was observed in all hybrids. The hybrids, PTGMS-38 x Sakha 106 (H10), PTGMS-38 x GZ8479 (H9), PTGMS-38 x Chinese 2 (H8), PTGMS-38 x Giza 177 (H6) and PTGMS-38 x Sakha 101 (H7) with standard heterosis of 54.47%, 54.03%, 51.63%, 50.98% and 49.24%, respectively over the best local check variety Giza 179 were considered as promising. Hence, these hybrid rice combinations may be used for commercial exploitation of two line hybrid rice breeding. Mean sum of squares due to genotypes showed significant differences for ten traits studied, indicating the presence of high genetic variability among the genotypes. The estimates of GCV were lower than the respective PCV, indicating the influence of environmental factor on the expression of the studied traits. Characters like, spikelet fertility % (99.12%, 47.21%), grain yield/plant (98.30%, 36.11%), plant height (99.20%, 35.28%), panicle weight (97.30%, 35.27%) and flag leaf area (89.32%, 31.97%) showed high heritability coupled with moderate genetic advance as percent of mean, suggesting that selection for the improvement of these characters may be rewarding and also greater role of non-additive gene action and suggesting heterosis breeding could be used to improve these characters. Based on ten studied characters, the genotypes were grouped into three clusters at 0.98% similarities coefficient.

Key words: Oryza sativa L., PGMS, genetic variability, heterosis