Z.A. Dar

Morphological and molecular characterization of maize inbred lines showing variability for drought tolerance

A set of hundred maize inbred lines were analyzed for resilience to moisture stress for twenty-four traits related to maturity, morphological, physiological, yield, quality and root traits. Evaluation confirmed a wide range of variability revealing significant response of main effects (lines, irrigations and years and their respective digenic and trigenic interactions). Fifteen elite identified lines performed well under moisture stress conditions showing inbuilt tolerance towards moisture stress. A set of 32 SSR markers, having genome-wide coverage, was chosen for genotyping the selected 15 inbred lines. These markers generated a total of 239 polymorphic alleles with an average of 7.47 alleles per locus. The minimum and maximum PIC value was 0.886 and 0.608 with a mean of 0.782. The coefficient of genetic dissimilarity ranged from 0.215 to 0.148. DARwin derived cluster analysis grouped 15 elite maize lines in three major clusters with five lines each in cluster-III and II and four lines in cluster-I with KDM-361A as root (at origin point. Molecular marker data however, confirmed diverse genetic nature of six lines (KDM-372, KDM-343A, KDM-331, KDM-961, KDM-1051 and KDM-1156) with favorable drought resilient traits with no yield penalty under moisture stress. Exploitation of these identified elite lines in involving all possible combinations helped to develop single cross hybrids under moisture stress conditions.

Advanced Breeding Strategies to Mitigate the Threat of Black Stem Rust of Wheat

Stem rust or black rust of wheat is caused by the fungus Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. Stem rust is known for causing severe devastations periodically in all wheatgrowing countries of the world. The most effective and environmentally sound method to control these diseases is through the deployment of resistant cultivars. Although a number of rust resistance genes have been identified in wheat (McIntosh et al., 2014), a major problem has been their short-lived effectiveness due to the fast emergence of virulent races of the pathogen that are capable of overcoming the resistance. For last several decades, epidemics of stem rust have been effectively controlled in most wheat growing regions because of the worldwide deployment of effective stem rust resistance genes in wheat varieties and removal of important alternate hosts, such as International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 6 (2017) pp. 1-20 Journal homepage: http://www.ijcmas.com

Genotype x environment interaction for forage yield and its components in oats (Avena sativa L.)

The present investigation was carried out to study stability performance over six environments for forage yield and its components in 12 genetically diverse genotypes of oats using a randomized complete block design. The partitioning of (environment + genotype x environment) mean squares showed that environments (linear) differed significantly and were quite diverse with regards to their effects on the performance of genotypes for forage yield and its yield components. Stable genotypes were identified for wider environments and specific environments with high per se performance (over general mean) for forage yield ha. The investigation revealed that the genotype SKO-90, SKO-96 and Sabzaar were desirable and stable across the environments. Other genotypes SKO-148, SKO-160, SKO-166 and SKO-167 were found to be suitable for favourable situations, while genotype SKO-20 was responsible to poor environments for forage yield.

Stability analysis for physiological traits, grain yield and its attributing parameters in oats (Avena sativa L.) in the Kashmir valley

Eleven genotypes of oats were planted at six diverse environments to assess genotype environment interaction and determine stable oat (Avena sativa L.) cultivar in Kashmir division for grain yield using randomized block design during 2014 to 2015. There was considerable variation in grain yield and physiological traits within and across environments. Stability analysis for grain yield was conducted to check the response to Genotype x Environment interactions. The mean squares due to G x E (linear) were significant depicting genetic differences among genotypes for linear response to varying environments. Mean squares due to pooled deviations were highly significant, reflecting considerable differences among genotypes for non-linear response. Out of eleven genotypes, only three oats lines i.e., SKO-98, SKO-166 and Sabzaar, showed non-significant deviation from regression and their regression coefficient values were close to unity and desirable for grain yield across the environments. The cultivar, “SKO-98” with respective regression coefficient value of 1.018, the smallest deviations from regressions (Sdi) value (0.025) and the above average grain yield could be considered the most widely adapted cultivar.

Genetic Diversity of Maize (Zea mays L.) Genotypes Assessed by SSR Markers under Temperate Conditions

Genetic Diversity of Maize (Zea mays L.) Genotypes Assessed by SSR Markers under Temperate Conditions A set of twenty four maize lines comprising fifteen drought promising inbred lines, four drought susceptible inbred lines and five drought tolerant checks were analyzed for molecular characterization. These inbred lines belong to AICRP (All India Co-ordinated Research Programme) Maize Srinagar Centre and the checks were selected from CIMMYT (International Maize and Wheat Improvement Centre) material.. Molecular characterization was done using a set of 45 SSR markers having genome wide coverage. The marker data was analyzed using Power Marker Software (Version 3.25). The markers detected a total of 271 alleles with an average of 8.46 alleles per locus in twenty four maize lines. The average polymorphism information content (PIC) ranged from 0.56 and 0.89 with a mean of 0.78. The level of heterozygosity in the inbred panel was significantly low. The mean value of heterozygosity was 0.05 implying that most of the loci attained homozygosity. Dendrogram derived from UPGMA cluster analysis showed presence of two major clusters, one of which had many subgroups. Phenotyping of these inbreds was done by using morphological, maturity, physiological, yield and yield attributing traits. Genotyping data complemented by phenotyping data would be used to identify a number of pairwise combinations for the development of mapping populations for drought tolerance related traits and potential heterotic pairs for the development of drought tolerant hybrids...

Breeding value, parent offspring regression and trait association for agronomic and quality traits in rice (Oryza sativa L.)

To estimate breeding value, correlation and heritability in rice, two parental lines of rice, Mushk Budji and DHMAS 70Q 164-1b were crossed to generate F1 plant that was subsequently backcrossed to raise 29 BC1F1 plants. The best performing single BC1F1 plant was selected and selfed to raise BC1F2 population. The selected 14 BC1F2 plants were advanced to raise 104 BC1F2: 3 individuals. The observations were recorded on parents, BC1F1, BC1F2, BC1F2: 3 individuals for 13 agronomic and quality traits. The line SKUA-485 27–47 recorded high breeding values for all the traits. This line is expected to yield progenies having high grain yield and contributing traits. The parent offspring regression (rOP) is a direct measure of heritability in broad sense and was worked out using BC1F2 and BC1F2: 3 progenies and PH recorded high positive b-value of 0.75. The grain shape as measured by kernel length: breadth ratio showed high h2 (0.58). The highest correlation was recorded between traits grain yield and effective tillers per plant (r=0.760). Milled rice length recorded significant positive correlation with kernel length: breadth ratio and kernel length after cooking, while it showed negative but significant correlation with elongation ratio. Backcross generations particularly from genotype SKUA-485-27-47 were expected to recover progenies with more number of effective tillers per plant, high grain yield and short bold grain type.

Genetic effects of combining ability on forage quality traits and forage yield in diallel crosses of oats (Avena sativa L.)

Studies in oats (Avena sativa L.) were carried out to generate information on combining ability (general and specific), nature and magnitude of gene effects and heterosis for forage quality and yield. The experimental material comprised of 10 diverse parents and 45 F1 crosses (excluding reciprocals) generated through a 10 x 10 diallel mating design. Significant interaction between combining ability effects were observed for all the quality traits and yield. The estimates of additive variance were higher in magnitude than their corresponding dominance variance estimates indicating the role of additive gene action, except green forage yield and dry matter yield. The parent SKO-213 had highly significant and desirable GCA effects for crude protein content, SKO-210 for neutral detergent fibre, SKO-204 for acid detergent fibre, SKO-208 for crude fibre parent, SKO-207 for ash content and SKO-212 for both green forage and dry matter yields. Cross combinations viz., SKO-212 x SKO-213, SKO-204 x SKO-211, SKO-205 x Sabzaar, Sabzaar x SKO-212 and SKO-205 x SKO-211 exhibited high and desirable sca and heterobeltiosis effects simultaneously for all the quality traits, green forage yield and dry matter yield ha−1.