STUDIES ON SEEDLING COLD TOLERANCE IN SORGHUM
KrishiKosh
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Title |
STUDIES ON SEEDLING COLD TOLERANCE IN SORGHUM
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Creator |
BIRANWAR NIRANJAN INDRARAJ
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Contributor |
RADHA KRISHNA, K.V
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Subject |
STUDIES, SEEDLING, COLD, TOLERANCE,SORGHUM
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Description |
The salient inferences drawn from the results obtained from the investigations on “STUDIES ON SEEDLING COLD TOLERANCE IN SORGHUM (Sorghum bicolor (L.) Moench)” comprising 128 genotypes are as given below. Keeping in this view, investigations on “studies on seedling cold tolerance in sorghum” were undertaken to elucidate the information on tolerance to cold stress. The main aim was to understand and quantify various components of seed quality in relation to cold tolerance, to identify simple techniques that would reliably determine germination under cold condition, and identify cold tolerant lines to breed further for cold tolerance. From the results it is evident that the important selection criteria that determine tolerance under cold are: germination percentage of seed, Vigour index, rate of germination and dehydrogenase activity. Hence rapid germination and vigourous growth of sorghum seedlings under cool (10o C) soil conditions is a significant cold tolerant trait. Temperature sensitive processes in seedling establishment include germination, growth and emergence. The shoot length would be expected to follow differences in rate of germination. In practice, all genotypes being selected for seeding in cold conditions need both rapid germination and good seedling vigour when temperatures are normal as well as a high level of tolerance to colder conditions when seeded early. Thus, the evaluation of seedling growth, early seedling vigour, rate of germination under normal and cold temperatures is useful for identifying genotypes with early seedling vigour better rate of seed germination for calculating cold tolerance per se (relative reduction of normal performance). The analysis of the results evidently brings out the variable significant influences of cold stress on genotypes and various seed and seedling traits. The correlations worked out and the variabilities understood from the statistical analysis, including the heritability components and genetic advancement has clearly brought out strong linkages among few of the seed and seedling traits to categorize them into the best among hybrids and varieties, parental lines, germplasm lines and advanced lines in AICSIP trials. Therefore, the important selection criteria that determine tolerance under cold are: germination percentage of seed, vigour index, rate of germination and dehydrogenase activity. The cold tolerant genotypes identified are CSH 9, CSH 14, CSH 15R, CSH 23, CSH 16, CSH 18 (Hybrids), CSV 23, M 35-1, RS 29, CSV 19, I 12 (varieties), 27 B, 104 A, 2219 B, 2077 A, 2077 B, AKMS 14B (Parental lines), AVHT-SS 601, AVHT-SS 607, AVHT-SS 611, AVHT-SS 617, AVHT-SS 626, AVHT-SS 624, AVHT-SS 627, AVHT-SS 701, AVHT-SS 705, AVHT-SS 714 (Advanced lines in AICSIP), IS 10940, IS 303, IS 305, IS 311, IS 3762 (Germplasm lines) Hence, in conclusion, the breeding efforts should be in the direction that will evolve seeds with requisite cold tolerance in the desirable agronomic background to increase productivity in cooler environments. Therefore, the future line of work should focus on the task of deriving cold tolerant hybrids and varieties with good agronomic background with following objectives: 1. To evaluate genotype × environment effects on fertility restoration under cold temperatures and identify cold tolerant lines to further enhance for cold tolerance in hybrid parents 2. Characterize germplasm sources for cold and integrate these genes into elite genetic backgrounds, and 3. Develop mapping populations and identify molecular markers for cold tolerance in sorghum CHAPTER I INTRODUCTION Sorghum (Sorghum bicolor (L) Moench) is one of the most important cereal crops cultivated in the world next to Wheat, Rice and Maize. The crop is grown for food, feed and fodder. It is dietary staple of more than 500 million people in more than 30 countries. India now produce about the same amount of 8.0 m t of sorghum grain from much reduced area of 8.45 m ha (2007-08), what it used to produce from about 18 m ha in the 1970’s. Area under kharif sorghum has come down from 10.7 m ha to less than 4.0 m ha over the last 30 years. Declining in Rabi area is not drastic (from 6.8 m ha to 4.9 m ha during same period). Maintaining the production level is made possible only largely through productive hybrids and varieties and improved production technologies developed by the central and state programmes. During the last three decades, productivity has gone up by 84.0% in case of kharif sorghum and 70% in rabi sorghum. This has enabled the country to spare > 8.0 m ha land (in most cases fertile land with even supplementary irrigation facility) for the horizontal spread of commercial crops such as oil seeds, pulses, soybean and even maize and Bt cotton in recent years. The kharif sorghum is grown in Maharashtra, Karnataka, Madhya Pradesh, Andhra Pradesh, |
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Date |
2016-08-06T13:38:06Z
2016-08-06T13:38:06Z 2010 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/71256
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Language |
en
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Relation |
D8575;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD
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