physicochemical
Contents of 39(1 & 2) 2011 - acharya ng ranga agricultural university
Contents of 39(1 & 2) 2011 - acharya ng ranga agricultural university
- No tags were found...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
J.Res. ANGRAU 39(1&2)28-33, 2011<br />
COMBINING ABILITY ANALYSIS FOR YIELD AND YIELD COMPONENT TRAITS<br />
IN RICE (Oryza sativa L.)<br />
P. SAIDAIAH, M.S. RAMESHA, S. SUDHEER KUMAR and J.SURESH<br />
Department of Genetics and Plant Breeding,<br />
College of Agriculture, Acharya NG Ranga Agricultural University, Rajendranagar, Hyderabad – 500 030<br />
ABSTRACT<br />
One hundred and fifteen hybrids were developed utilizing Line (5 CMS lines) x Tester (23 testers) fashion.<br />
The hybrids along with parents were evaluated for eight characters during kharif, 2007 at RARS, Warangal to<br />
understand the gene action in rice. The combining ability analysis revealed significant differences among the<br />
parents for all the characters studied indicating the predominance of dominance gene action in governing yield and<br />
related traits. This suggests the possibility of exploiting heterosis. Two CMS lines (APMS 6A and CRMS 32A) and<br />
six testers (1096, 612-1, GQ-70, GQ-120, KMR 3 and SG 27-77) were found to be good general combiners for yield<br />
and other yield attributes. The hybrids APMS 6A x 612-1, PUSA 5A x KMR-3, CRMS 32A x IR 43 exhibited higher<br />
specific combining ability with at least one of the parent possessing positive alleles for grain yield. The interrelationship<br />
of sca with sca revealed that predominance of non additive gene action viz., additive x dominance and dominance<br />
x dominance type for gene interaction for most of the hybrid combinations which could be exploited for heterosis<br />
breeding programme in rice.<br />
Substantial increase in rice (Oryza sativa L.)<br />
production can be achieved only with the use of<br />
suitable hybrids. This can be further hastened by<br />
choice of suitable outstanding parents with favourable<br />
alleles, which on crossing would give heterotic<br />
hybrids. The line x tester analysis of combining ability<br />
proposed by Kempthorne (1956) is the most common<br />
method used to find out the general and specific<br />
combiners and study the nature of gene action<br />
governing the inheritance of different characters. The<br />
main objective of this investigation was to identify<br />
good general and specific combiners for yield and its<br />
component characters.<br />
MATERIALS AND METHODS<br />
Five CMS lines viz., IR 58025A, IR 79145A,<br />
APMS 6A, PUSA 5A and CRMS 32A were crossed<br />
with 23 diverse elite restorers selected from rice<br />
germplasm maintained at Directorate of Rice<br />
Research (DRR), Hyderabad during rabi, 2006 using<br />
line x tester design. The resultant 115 F 1<br />
s and 28<br />
parents were grown in Complete Randomized Block<br />
Design with two replications during kharif, 2007 at<br />
Regional Agricultural Research Station, Warangal,<br />
Andhra Pradesh. Two hybrids (KRH 2 and PA 6201)<br />
and two pure lines (Jaya and IR 64) were used as<br />
standard checks. Twenty 25 days old seedlings were<br />
transplanted at a spacing of 20 x 15 cm and all the<br />
recommended agronomic practices were followed. In<br />
each entry, five plants were selected randomly from<br />
each replication and biometrical observations were<br />
recorded for plant height, productive tillers per plant,<br />
panicle length, panicle weight, filled grains per panicle,<br />
spikelet fertility %, 1000 grain weight and grain yield<br />
per plant. Days to 50% flowering was recorded on<br />
plot basis. The mean data were analyzed for<br />
combining ability following the standard method of<br />
Kempthorne (1956).<br />
RESULTS AND DISCUSSION<br />
Presence of significant and high variance due<br />
to genotypes for all the traits studied (Table 1)<br />
indicated the existence of wide variability among the<br />
genotypes. The combining ability variance of lines<br />
and testers was significant for productive tillers per<br />
plant and filled grains per panicle. In addition, the<br />
lines for panicle weight, spikelet fertility, grain yield<br />
plant -1 and productivity day -1 were also showed<br />
significance. The high and significant mean squares<br />
of lines x testers revealed that lines and testers<br />
interacted and produced markedly different combining<br />
ability effects and it might be due to wide genetic<br />
diversity of lines and testers. The estimates of<br />
variance due to SCA were much higher than that of<br />
due to GCA variances for all the nine characters<br />
revealing the importance of dominance and epistatic<br />
Email: saidu_genetics@yahoo.co.in<br />
28