PREFERENTIAL PAIRING OF CHROMOSOMES IN A TETRAPLOID HYBRID BETWEEN ORYZA GLABERRIMA AND O. SATIVA

1968 ◽  
Vol 10 (3) ◽  
pp. 527-535 ◽  
Author(s):  
Hiko-Ichi Oka

A tetraploid hybrid was obtained from a cross between induced tetraploid strains of Oryza sativa L. and O. glaberrima Steud., which differed in glutinous (waxy) vs. non-glutinous starch (gl: +) and other genes. In the hybrid, as compared with the parental strains, there was a reduced number of quadricvalents and a relatively high degree of fertility. Segregation ratios for the glutinous gene observed in the back-cross and F2 generation appeared to be modified not only by preferential homogenetic pairing but also by gametic selection. Taking into account the effect of gametic selection estimated from simplex heterozygotes, it was suggested that preferential pairing could take place to a certain extent. It seems to be difficult to measure quantitatively the degree of preferential pairing in tetraploid species hybrids, unless the effect of various segregation-distorting factors can be accounted for.

2013 ◽  
Vol 5 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Srikrishna LATHA ◽  
Deepak SHARMA ◽  
Gulzar S. SANGHERA

The nature and magnitude of heterosis and combining ability was studied in 18 F1 hybrids involving three CMS lines and six testers using line × tester analysis. The analysis of variance for combining ability of all the traits showed that variances due to treatments, parents, hybrids were highly significant. The line ‘CRMS 32A’ and testers viz. ‘Super rice-8’, ‘R 1099-2569-1-1’ and ‘Jitpiti’ were identified as good general combiners. The significant differences between lines x testers interaction indicates that SCA attributed heavily in the expression of these traits and demonstrates the importance of dominance or non additive variances for all the traits. The hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’ and ‘APMS 6A’/‘Super rice-8’ were promising for grain yield. The magnitude of relative heterosis, heterobeltiosis and standard heterosis were also estimated for different characters. A high degree of relative heterosis was observed for grain yield (20.45- 82.37%) in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘APMS 6A’/‘Super rice-8’, ‘APMS 6A’/‘Jitpiti’ and ‘CRMS 32A’/‘R 1099-2569-1-1’. While, a higher degree of: heterobeltiosis (13.60 -68.37%) was observed for grain yield in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘CRMS 32A’/‘R 1099-2569-1-1’, ‘APMS 6A’/’Super rice-8’ and ‘APMS 6A’/’Jitpiti’. A high degree of standard heterosis was observed for grain yield in the hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’. The hybrid ‘CRMS 32A’/ ‘R 1099-2569-1-1’ recorded a high degree of relative heterosis (62.01%), heterobeltiosis (57.35%) and standard heterosis (15.05 and 25.51% over check hybrids, ‘Mahamaya’ and ‘Indirasona’, respectively) that can be tested on yield trials for its further testing over locations.


1994 ◽  
Vol 63 (4) ◽  
pp. 632-637 ◽  
Author(s):  
Yasuo TAKASAKI ◽  
Yoichi SEKI ◽  
Hirosi NOJIMA ◽  
Akihiro ISODA

2017 ◽  
Vol 62 (4) ◽  
pp. 361-369
Author(s):  
Hassan Kasim ◽  
Ibrahim Musa ◽  
Mustapha Muhamman

Poor agronomic practices coupled with herbicide mismanagement influence crop performance, yield, weed infestation and environmental hazards. Thus, field experiments were carried out to investigate the effect of spacing and reduced levels of butachlor on weed control and yield of NERICA 1 rice (Oryza sativa L. x Oryza glaberrima L). The experiments were conducted in the 2011 rainy season at the Teaching and Research Farm of the Department of Crop Production and Horticulture, Modibbo Adama University of Technology, Yola, and Lake Gerio, Yola in the 2012 dry season. Yola is located between latitude 9o14? N and longitude 12o28? E in the Northern Guinea Savanna ecological zone of Nigeria. Treatments consisted of four spacings (20 cm x 20 cm, etc.) and four butachlor levels (3, 2, 1, and 0 kg ha-1 a.i.). The experiments were laid out in a split-plot design with spacings assigned to the main plot and butachlor levels assigned to the sub-plot and were replicated three times. Data were taken on percentage establishment, number of leaves per plant, general weed cover, panicle length and grain yield per hectare. Data generated were subjected to analysis of variance. Means showing a significant F-test were separated using LSD. Results obtained showed that butachlor at 1 kg ha-1 and 14 cm x 14 cm spacing gave the highest grain yield of 1441 kg ha-1 and maximum weed control. They are, therefore, recommended for adoption by farmers in Yola and similar environments.


Crop Science ◽  
2012 ◽  
Vol 52 (2) ◽  
pp. 524-538 ◽  
Author(s):  
Marie Noelle Ndjiondjop ◽  
Koichi Futakuchi ◽  
Fousseyni Cisse ◽  
Hugues Baimey ◽  
Roland Bocco

Sign in / Sign up

Export Citation Format

Share Document