Studies on Genetic Variability, Heritability and Genetic Advance Estimates in Newly Developed Maize Genotypes (Zea Mays L.).

The present study was carried out at Research farm, College of Agriculture, ANGRAU, Rajendranagar, Hyderabad during kharif, 2011 to determine the various parameters of genetic variability, broad sense heritability and genetic advance estimates in newly developed 65 maize genotypes. Analysis of variance revealed that the mean sum of squares due to genotypes showed significant differences for all the 11 characters studied. High to moderate estimates of GCV and PCV were recorded for Grain yield, number of kernels per row, 100-kernel weight, ear length and plant height which represents considerable variability and offers scope for genetic improvement through selection. Grain yield, number of kernels per row, 100-kernel weight, ear length and ear height had high GCV estimates with high heritability. Moderate estimates of genetic advance with high heritability was recorded for Grain yield, number of kernels per row, 100-kernel weight, ear length, ear height and plant height which further leads to improvement of traits under selection. Thus provides better opportunities for selecting plant material for these traits in maize breeding program.

Screening of Rice Genotypes for Thermotolerance BY TIR Technique.

Production of rice--the world's most important crop for ensuring food security and addressing poverty will be defeated as temperatures increase in rice-growing areas with continued climate change. Climate change needs us to look at various alternatives for more drought tolerant and tougher strains and to develop a technique to screen a large number of genotypes for high temperature tolerance. Adapting temperature induction response (TIR) technique 100 rice genotypes were screened for thermotolerance. Significant variation for acquired thermotolerance was observed in 100 rice lines. From the 100 genotypes 30 were exhibits themotolerance to induced high temperature.

Identification of Rice Genotypes for Drought Tolerance Based on Root Characters.

Climate change needs us to look at various alternatives for more drought tolerant and tougher strains. Rice (Oryza sativa L.) is the most important food crop of the world; drought stress is a serious limiting factor to rice production and yield stability in rainfed areas. In order to design efficient varieties with virtues of drought tolerance and high yielding ability is necessary. Root system plays an important role under drought conditions. Among all the genotypes NLR 33671 showed highest root length (27.6cm) under moisture stress condition followed by NLR 3010 (24.5cm), NLR 40059 (23.6 cm), TELLAHAMSA (23.5 cm) ,NLR 40049 (23.5), NLR 3098 (23.5) were showed significantly superior mean values than remaining genotypes for most of the root traits included in this study. Therefore, these genotypes can be considered as drought resistance varieties. Whereas NLR 40054 (14.35 cm), BPT 5204 (14.55 cm), NLR 40045 (15 cm) and NLR 30491 (15.19cm) recorded lowest root length these can be consider as susceptible ones. The effects of drought stress on rice productivity were explicitly parameterized and addressed in the present study.

Relative water content as influenced by varied plant densities and irrigation levels in pigeonpea.

A field experiment was conducted on a sandy clay soil at Agricultural Research Station, Basanthpur, Medak district of Andhra Pradesh during the kharif seasons of 2009-‘10 and 2010-’11 to study the variation in relative water content (RWC) of pigeonpea (Cajanus cajan (L) Mill Sp.) as influenced by plant densities and supplemental irrigation through drip. Three varied plant densities of pigeonpea (D1–55,555 plants ha- 1, D2–41,666 plants ha-1 and D3–33,333 plants ha-1) were tested as 3 main treatments with 4 irrigation levels as sub treatments involving control (I1 - rainfed), drip irrigation at flowering with 20 mm depth of water (I2), drip irrigation at pod development with 20 mm depth of water (I3) and drip irrigation at flowering and pod development with 20 mm depth of water at each stage, respectively (I4). The RWC was estimated at 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 days after sowing and at harvest. Daily evaporation and rainfall were also recorded at the experimental site. The crop in lower plant density of D3 had higher relative water content in comparison to D2, intermediate and D1, higher plant densities at flowering and pod development stages irrespective of the irrigation treatments imposed. Further, supplemental irrigation at flowering and pod formation stages showed marginal rise in the relative water content irrespective of densities. Lowest relative water content was recorded under nonirrigated rainfed control (I1) at higher plant densities of D1 both at flowering and pod development stages.