I= RECURRENT SELECTION FROM MAYDIS LEAF BLIGHT RESISTANCE AND GRAIN YIELD IMPROVEMENT IN MAIZE
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Title of Thesis
RECURRENT SELECTION FROM MAYDIS LEAF BLIGHT RESISTANCE AND GRAIN YIELD IMPROVEMENT IN MAIZE

Author(s)
Syed Salim Shah
Institute/University/Department Details
NWFP Agricultural University Peshawar/ Faculty of Crop Production Sciences
Session
2006
Subject
Plant Breeding and Genetics
Number of Pages
101
Keywords (Extracted from title, table of contents and abstract of thesis)
Recurrent selection, selection response, selection differential, S1 lines, heritability, maydis leaf blight

Abstract
Leaf blight of maize (Zea mays L.) caused by Bipolaris maydis (Nisik. And Miyake) is one of the major factors limiting maize production in the plain areas of Pakistan. Particularly in the North West Frontier Province (NWFP). The objectives of this study were to estimate heritability, selection differential, expected and observed response to selection for amydis leaf blight resistance grain yield maturity and plant and ear height and to determine progress from selection in two maize populations. Two cycles of S1 recurrent selection were conducted in broad based maize populations. Sarhad White (SW) and Azam. One hundred S1 lines of each population were compared with their respective original populations as checks. The experimental material was evaluated under artificial epiphytotics during 2003 and 2004 at NWFP Agriculture University Peshawar. Selection differentials, expected responses and heritability estimates were determined from the replicated S1 lines of the second cycle that were generated after random mating of selected S1 lines of the first cycle. Significant variations between the cycles were observed for all the traits except maturity. High heritability estimates. Desirable selection differentials and close correspondence of expected and observed response were manifested fro all the characters. Days to tasseling silking and pollen shedding decreased non-significantly in SW (3.01, 4.07 and 3.66% cycle-1) but approximately 1% cycle-1 increase was observed of maturity traits in Azam. Ear height and plant height were significantly increased in SW (20.97 and 17.52% cycle-1) while significantly decreased in Azam population by 6.87 and 3.23% cycle-1, respectively. Blight disease was significantly reduced from 2.9 to 2.3 in SW and from 3.1 to 2.5 in Azam population. One the other hand grain yield was significantly increased in SW from 2041 kg ha-1cycle-1 to 2528 kg ha-1 cycle-1 or 19.24% cycle whereas from 2346 kg ha-1 cycle to 2772 kg ha-1 cyucle-1 or 15.34% cycle-1 respectively. These findings suggested that S1 recurrent selections is effective in improving disease resistance and grain yield. However some additional cycles of selection may be necessary to further improved grain yield and resistance level to maydis leaf blight in these two maize populations.

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
99.06 KB
2 1 Introduction 1
42.06 KB
3 2 Review Of Literature 4
261.27 KB
4 3 Materials And Literature 25
88.29 KB
5 4 Results 33
245.69 KB
6 5 Discussion 59
215.88 KB
7 6 Sumarry 71
41.4 KB
8 7 Conclusions And Recommendations 74
16.37 KB
9 8 Literature Cited 75
115.5 KB
10 9 Appendices 82
250.42 KB