Year 2017, Volume 63 Issue 1 (31.03.2017)

Year : 2017
Volume : 63
Issue : 1 (31.03.2017)
   
Authors : Mahmoud Reza KARIMISHAHRI, R.C. SHARMA
Title : INHERITANCE OF RESISTANCE TO MAYDIS LEAF BLIGHT IN MAIZE
Abstract : Maize suffers from the threat of various diseases resulting in considerable yield losses. One of them is maydis leaf blight (MLB) an economically important disease incited by Bipolaris maydis (Nisikado and Miyake) Shoemaker. Analysis of variance for combining ability indicated that both GCA and SCA variances were highly significant for disease reaction studied. High GCA variance for disease reaction suggested operation of additive gene action. Out of the 6 parents 3 exhibited –ve and 3 exhibited +ve GCA effects for resistance to B. maydis. Resistance in inbred V-17 had the highest negative GCA effects hence it is the best general combiner for resistance. The estimates of SCA effects indicated several crosses showing -ve SCA effects. Out of the 15 hybrids only 5 hybrids showed significantly –ve SCA effects. Highest estimates of SCA effects were observed in the cross V-335 x V-13 followed by V-327 x V-17 and V-128 x V-17. Parent V-13 (with significant negative GCA effect) when crossed with parent V-335 (with significant negative GCA effects) gave hybrid V-335 x V-13 which had significant negative SCA effects. Parent V-17 (with significant negative GCA effect) when crossed with parent V-128 (with significant positive GCA effects) resulted in a hybrid which had significant negative SCA effects. Amongst resistant x resistant cross only V-335 x V-13 indicated heterosis both over mid parents and better parental values. The crosses involving V-13, V-17 and V-335 with susceptible lines indicated maximum heterosis for resistance. While the mean effects were highly significant for the eight resistant crosses the a and d effects were significant for only 4 crosses of the a and d effects. Though each of the three digenic epistatic effects dd was playing a greater role followed by ad effects in the resistance crosses. In V-335 x V-13 cross, dd effect was significant and negative. The relatively high magnitude and positive effects of dd in most of the crosses indicated that these interactions was enhancing susceptibility, while considering the CM-128 x V-335, CM-128 x V-13, CM –128 x V-128, CM-128 x V-17 and V-327 x V- 335 crosses were observed that ad and dd effects were highly significant and positive value.
For citation : Karimishahri R. M. , Sharma R.C., (2017) Inheritance of resistance to maydis leaf blight in maize, Agriculture and Forestry, 63 (1): 261-275. DOI: 10.17707/AgricultForest.63.1.29
Keywords : India, GCA, SCA, Maize, Bipolaris maydis
   
download paper

 

Search

Author (s) :
Title :
Keywords :
r