STUDIES ON ASSESSMENT OF GENETIC VARIABILITY FOR SEED VIGOUR UNDER HIGH TEMPERATURE IN MAIZE (Zea mays L.)
KrishiKosh
View Archive InfoField | Value | |
Title |
STUDIES ON ASSESSMENT OF GENETIC VARIABILITY FOR SEED VIGOUR UNDER HIGH TEMPERATURE IN MAIZE (Zea mays L.)
|
|
Creator |
RAJESH, P
|
|
Contributor |
RAMESH, T
|
|
Subject |
biological phenomena, biological development, maize, planting, genotypes, tolerance, genetics, proteins, chlorophylls, germinability
Zea mays L. |
|
Description |
Maize grown in more than 166 countries for diverse uses, in different seasons and different agro-ecological conditions. In India, maize is grown in a wide range of climates, extending from extreme semi-arid to sub-humid to temperate conditions. The total cultivated area for maize in India is 8.17 million hectares having production of 19.73 million tonnes with average productivity of 2.41 tonnes ha-1 (2009-10). The maize area under irrigation has increased marginally from ~11% (1950-51) to only ~20%. Most of the crop area under rainfed condition suffers from abiotic stresses like moisture stress, high and low temperature stress, salinity and nutrient stresses frequently limit growth and productivity of major crop species such as maize. High temperature stress has been the 2nd major abiotic problem after drought that reduces grain yield by more than 15 per cent. Therefore, to sustain the agricultural production it is necessary to breed varieties which are tolerant to high temperature stress. An efficient technique called Temperature Induction Response (TIR) Technique was developed for identifying high temperature tolerant lines. By employing TIR protocols have been standardized in maize. Optimum lethal and induction temperatures were assessed for seedling survival and growth during recovery. Using these protocols, 15 maize hybrids were screened for temperature tolerance. The results revealed that 53°C for 3 h where the mortality of seedlings was 80 per cent was considered as optimum lethal temperature and 52°C for 2 h considered as optimum lethal temperature for recovery growth where there was 80% reduction in growth. 35°C – 1h + 40°C – 1h + 45°C – 2h was considered as optimum induction temperature for both seedling survival and growth during recovery as there was maximum recovery after inducing them to lethal temperature. By using these protocols, genotypes like Kaveri50, 30V92 and RHM25 were identified as temperature tolerant and KHM218, GHM145, GK3060, and BIO9637 as temperature susceptible genotypes. The experiment material was further validated by allowing the seedling to grow up to 21 days in plastic containers and their growth was assessed. The supporting data for temperature tolerance was recorded in terms of two parameters namely dry weight and chlorophyll content. Upon perusal of data it has been clear that induction treatments influenced all the growth stages studied. The TIR protocols can be used to screen straight varieties / single cross hybrids that have become popular with seed companies and also farmers |
|
Date |
2016-06-09T13:45:10Z
2016-06-09T13:45:10Z 2011 |
|
Type |
Thesis
|
|
Identifier |
http://krishikosh.egranth.ac.in/handle/1/67109
|
|
Language |
en
|
|
Relation |
D8876;
|
|
Format |
application/pdf
|
|
Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
|
|