Publications by authors named "Rajib Roychowdhury"

3 Publications

  • Page 1 of 1

The Israeli-Palestinian wheat landraces collection: restoration and characterization of lost genetic diversity.

J Sci Food Agric 2020 Aug 18;100(11):4083-4092. Epub 2019 Jul 18.

Department of Vegetables and Field Crop, Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel.

Background: For over a century, genetic diversity of wheat worldwide was eroded by continual selection for high yields and industrial demands. Wheat landraces cultivated in Israel and Palestine demonstrate high genetic diversity and a potentially wide repertoire of adaptive alleles. While most Israeli-Palestinian wheat landraces were lost in the transition to 'Green Revolution' semi-dwarf varieties, some germplasm collections made at the beginning of the 20th century survived in gene banks and private collections worldwide. However, fragmentation and poor conservation place this unique genetic resource at a high risk of genetic erosion. Herein, we describe a long-term initiative to restore, conserve, and characterize a collection of Israeli and Palestinian wheat landraces (IPLR).

Results: We report on (i) the IPLR construction (n = 932), (ii) the historical and agronomic context to this collection, (iii) the characterization and assessment of the IPLR's genetic diversity, and (iv) a data comparison from two distinct subcollections within IPLR: a collection made by N. Vavilov in 1926 (IPLR-VIR) and a later one (1979-1981) made by Y. Mattatia (IPLR-M). Though conducted in the same eco-geographic space, these two collections were subjected to considerably different conservation pathways. IPLR-M, which underwent only one propagation cycle, demonstrated marked genetic and phenotypic variability (within and between accessions) in comparison with IPLR-VIR, which had been regularly regenerated over ∼90 years.

Conclusion: We postulate that long-term ex situ conservation involving human and genotype × environment selection may significantly reduce accession heterogeneity and allelic diversity. Results are further discussed in a broader context of pre-breeding and conservation. © 2019 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.9822DOI Listing
August 2020

Physiological, biochemical, and molecular mechanisms of heat stress tolerance in plants.

Int J Mol Sci 2013 May 3;14(5):9643-84. Epub 2013 May 3.

Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka 1207, Bangladesh.

High temperature (HT) stress is a major environmental stress that limits plant growth, metabolism, and productivity worldwide. Plant growth and development involve numerous biochemical reactions that are sensitive to temperature. Plant responses to HT vary with the degree and duration of HT and the plant type. HT is now a major concern for crop production and approaches for sustaining high yields of crop plants under HT stress are important agricultural goals. Plants possess a number of adaptive, avoidance, or acclimation mechanisms to cope with HT situations. In addition, major tolerance mechanisms that employ ion transporters, proteins, osmoprotectants, antioxidants, and other factors involved in signaling cascades and transcriptional control are activated to offset stress-induced biochemical and physiological alterations. Plant survival under HT stress depends on the ability to perceive the HT stimulus, generate and transmit the signal, and initiate appropriate physiological and biochemical changes. HT-induced gene expression and metabolite synthesis also substantially improve tolerance. The physiological and biochemical responses to heat stress are active research areas, and the molecular approaches are being adopted for developing HT tolerance in plants. This article reviews the recent findings on responses, adaptation, and tolerance to HT at the cellular, organellar, and whole plant levels and describes various approaches being taken to enhance thermotolerance in plants.
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http://dx.doi.org/10.3390/ijms14059643DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676804PMC
May 2013

Profiling of selected indigenous rice (Oryza sativa L.) landraces of Rarh Bengal in relation to osmotic stress tolerance.

Physiol Mol Biol Plants 2012 Apr 30;18(2):125-32. Epub 2012 Mar 30.

Centre for Biotechnology, Visva-Bharati, Santiniketan, 731235 West Bengal India.

A total of ten rare indigenous rice landraces of West Bengal were screened for germination potential and seedling growth under varying concentrations of sodium chloride (NaCl) and polyethylene glycol (PEG) solutions as osmotic stress inducing agents. Among the studied rice landraces Kelas and Bhut Moori showed highest degree of tolerance to induced osmotic stresses. Proline content of the studied lines was also determined. Genetic relationship among the studied rice landraces was assessed with 22 previously reported osmotic stress tolerance linked Simple Sequence Repeat (SSR) markers. The identified allelic variants in form of amplified products size (molecular weight) for each SSR marker were documented to find out allele mining set for the linked markers of the studied genotypes in relation to osmotic stress tolerance. A Microsatellite Panel was constructed for the different allelic forms (size of amplified products) of each used marker. Among 22 SSR markers, ten showed unique alleles in form of single specific amplified product for the studied four genotypes which can be used for varietal identification. Genetic relationship among the studied rice lines was determined and a dendrogram was constructed to reveal their genetic inter-relationship. Polymorphism Information Content (PIC) for each used marker was also calculated for the studied rice lines.
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http://dx.doi.org/10.1007/s12298-012-0110-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550497PMC
April 2012