مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

A partial diallel design was used among 20 maize inbred lines to form I 10 F1 hybrids to generate information on the values of these lines for developing insect resistant maize varieties during the short rains season o f 2006. The hybrids were evaluated for resistance to the C. partellus and B. fu sca , and for agronomic performance over two seasons during long and short rains of 2007 at a mid-altitude dry early maturity site at KARl Kiboko, and the moist mid-alt itude medium maturity site at KARl Embu. leaf damage score (using a scale of 1-9 where: 1= No damage and 9= extremely damaged), number of exit holes, cumulative tunnel length, and grain yield were measured as resistance traits. The gen otype sum of squ are was partitioned into general combining ability (GCA) and specific combining ability (SCA) effects. Maize inbred lines with good general combining ability for insect resistance including maize inbred lines with significant and negative GCAי s for leaf damage were identified as lines J2, 16,18, 19 and 20 at Kiboko and lines 8, 17, 18, and 20 in Embu. Results showed that the problem of stem borers intensified by over 40 % within four years in the experimental region of Eastern Kenya; currently mean yield loss due to stem borers was ass essed to be about 56%. Several hybrids had sign ificant negative SCA for leaf dam age and sign ificant positive SCA for gra in yield. The maize inbred lines studied rev ealed the ir potent ial for use in breeding prog ram s for insect resi stance that co uld result in a co rrelated response for increased grain yie ld. Recurr ent selection would be the best option to develop high yielding insect res istant germplasm for this region of Ken ya considering that additive gene action were predominant. Evidently, it would be more difficult to develop host plant resistance to B. fusca than to C. partellus .