Evaluation of CERES Maize model under Indian Temperate Conditions

Field experiments were conducted in India at Shalimar Campus of Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir during 2015 and 2016 to study the growth and yield of maize at different planting dates and nitrogen levels. Maize was simulated at different agro-ecological zones (altitudes) of Kashmir valley. Further, maize was evaluated at fixed dates with varied nitrogen levels and at fixed nitrogen level with varied dates of sowing. Experiment was laid in split plot design with three dates of sowing, i.e. 22nd May, 30th May and 8th June, assigned to main plot and four levels of nitrogen, i.e. 80 kg N ha-1 (N1), 120 kg N ha-1(N2), 160 kg N ha-1 (N3) and 200 kg N ha-1, assigned to sub plot. Genetic coefficients of maize crop variety (Shalimar Maize composite-4) were generated, calibrated and validated in CERES Maize model using DSSAT 4.5. Simulated studies carried atdifferent locations indicated that sowing of Maize on 30th May (D2) with 200 kg N ha-1 (N4) predicted highest grain yield in location Kokernag which was followed by location Srinagar on same date 30th May (D2) with 160 kg N ha-1(N3) and lowest yield was recorded in district Kupwara. Maximum Biological yield was also recorded at 30th May with 160 kg N ha-1 (N3). Among the district Kokernag recorded maximum biological yield with delayed maturity (160 days) simulation studies were carried out with 7 dates of sowing at fixed level of Nitrogen in all the districts. Simulated studies of maize showed that sowing on 30th May with 160 kg N ha-1 (N3) recorded maximumLeaf Area Index Biological yield and grain yield. However, highest grain yield was recorded at location Kokernag and lowest was recorded at location Kupwara

Delineating Marker-trait Associations for Fusarium Wilt in Chickpea using Axiom® Cicer SNP Array

Fusarium wilt (FW) caused by the Fusarium oxysporum f. sp. ciceri is a devastating disease of chickpea (Cicer arietinum L.). To identify promising resistant genotypes and genomic loci for FW resistance, a core set of 179 genotypes of chickpea was tested for FW reactions at seedling and reproductive stages under field as well as controlled conditions in the greenhouse. Our results revealed that at seedling stage, most of the genotypes were found resistant whereas, at the reproductive stage majority of the genotypes were found susceptible. Genotyping using a 50K Axiom®Cicer SNP Array and trait data of FW together led to the identification of 26 significant (p≤E-05) marker-trait associations (MTAs) for FW resistance. Among 26 MTAs, 12 were identified using trait data recorded in the field (3 at seedling and 9 at reproductive stage) and 14 MTAs were identified using trait data recorded under controlled conditions in the greenhouse (6 at seedling and 8 at reproductive stage). The phenotypic variation explained by these MTAs varied from 11.75 to 15.86% with an average of 13.77%. Five MTAs were classified as major, explaining more than 15% phenotypic variation for FW and two MTAs were declared stable, being identified in either two environments or at two growth stages. One of the promising stable and major MTAs (Affx_123280060) detected in field conditions at reproductive stage was also detected in greenhouse conditions at seedling and reproductive stages. The stable and major (>15% PVE) MTAs can be used in chickpea breeding programmes