Ajaz A. Lone

Transcription Factors and Plants Response to Drought Stress: Current Understanding and Future Directions

Increasing vulnerability of plants to a variety of stresses such as drought, salt and extreme temperatures poses a global threat to sustained growth and productivity of major crops. Of these stresses, drought represents a considerable threat to plant growth and development. In view of this, developing staple food cultivars with improved drought tolerance emerges as the most sustainable solution toward improving crop productivity in a scenario of climate change. In parallel, unraveling the genetic architecture and the targeted identification of molecular networks using modern “OMICS” analyses, that can underpin drought tolerance mechanisms, is urgently required. Importantly, integrated studies intending to elucidate complex mechanisms can bridge the gap existing in our current knowledge about drought stress tolerance in plants. It is now well established that drought tolerance is regulated by several genes, including transcription factors (TFs) that enable plants to withstand unfavorable conditions, and these remain potential genomic candidates for their wide application in crop breeding. These TFs represent the key molecular switches orchestrating the regulation of plant developmental processes in response to a variety of stresses. The current review aims to offer a deeper understanding of TFs engaged in regulating plant’s response under drought stress and to devise potential strategies to improve plant tolerance against drought.

Effect of Drought On The Germination of Maize Using PEG (Polyethylene Glycol) As A Substitute For Drought Screening

Drought stress is one of the most important environmental factors in reduction of growth, development and production of plants. Germination of each seed is considered as one of the first and most fundamental life stages of a plant so that, the success in growth and yield production is also depending on this stage. To study the effect of PEG stress on germination and early seedling stages on maize, an experiment were laid out at laboratory conditions of Division of Genetics and Plant Breeding SKUAST-K FoA/RRS Wadura. This investigation was performed as factorial experiment under Complete Randomized Design (CRD) with three replications. Polyethylene glycol stress induced in laboratory caused progressive decline in both the parameters across all genotypes with increase in Polyethylene glycol from 0-20% and both the parameters (length of radical and root biomass) had highest value under control.

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

Genetic variability in saffron (Croccus sativus L.) clones

The present investigation was carried out at saffron research station pampore, SKUAST-Kashmir during 2010. Fifty clones were planted in a randomized bock design with three replications. Observations were recorded on 10 randomly selected and tagged competitive plants for 11 morphological, physiological, floral and corm traits viz, plant height (cm), number of radical leaves per plant, stomatal frequency, stomatal size (microns), chlorophyll content (%), number of flowers per corm, fresh pistil weight per corm (mg), pistil length (cm), stigma length (cm), number of daughter corms/mother corm and average weight of daughter corms per mother corm (g). Genotypic differences were highly significant for all the tested traits. Components of variability indicated that a wide range of variability existed for number of flowers per corm (0.80–1.96), fresh pistil weight corm−1 (29.00–65.46), pistil length (4.05–5.83), plant height (23.20–35.60), stomatal frequency (11.20–16.40), stomatal size (microns) (21.03–51.18), number of daughter corms/mother corm(3.46–9.30), average weight of daughter corms per mother corm (g) (3.04–10.60) and number of radical leaves per plant (15.40–26.60). Per se performance of genotypes under evaluation revealed a gross fresh pistil weight of 46.36mg corm−1 from 1.26 flowers corm−1 resulting in 3 kg laccha ha−1 with planting density of 5 lakh corms ha−1 showing an increase of 26% over state average. Estimates of phenotypic variance were higher than the corresponding estimates of genotypic variance, thereby revealing influence of environment in the expression of the traits studied. High values of heritability were recorded for all the traits.

Quantitative Estimation of Genetic Variability in Morphological Characteristics of Eastern Cottonwood (Populus deltoides Bartr.) Clones

The study was carried out to analyze the genetic variability for different growth parameters in poplar clones at the age of 2 and 3 yr in the nursery. Forty-nine exotic and indigenous clones of poplar were evaluated for eight morphological traits. Clones were planted in randomized block design (RBD) with three replications with four clones in a block in each treatment. Observations for different characters were recorded on six selected competitive clones per genotype. Results showed a high interclonal variability for most parameters. Statistically significant differences among clones indicated that the majority of study characters are controlled by genetic factors, specific to each clone. Highly significant genotypic difference supported by wide range of variation of mean and range values were observed for the characters under study. Significant and positive correlation was observed between diameter at breast height (DBH) and plant height. Leaf lamina length showed positive and significant correlation with petiole length, total leaf length, leaf width, and L/B ratio. Total leaf length showed positive and significant correlation with leaf width and L/B ratio. High estimates of heritability (in a broad sense) were observed for almost all characters in the study. High genetic advance expressed as percent of mean was recorded for petiole length (60.90), followed by plant height (60.78) and collar diameter (44.19) at 2 yr. At the age of 3 yr, genetic advance was found maximum for petiole length (60.05), followed by collar diameter (47.62) and plant height (45.29). The efforts for selecting new clones and their field-testing must continue under a long-term improvement plan so that the best clones can be recommended for plantations and hybridization programs.