Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
Breeding of crops chosen yield over other attributes such as stress tolerance, which could be
restored under farmers’ supervision and other agricultural methods. Therefore, when compared
to the present-day crop varieties, wild cultivars of crops could practically tolerate and survive
under an extensive scale of weather variations and unfavorable habitats. Hence, the wild
cultivars of different crop plants can be regarded as a principal pool of genetic diversity and it
should be given more importance for exploration of their stress-tolerant characteristics. Besides
the genetic resources from wild cultivars, genes from diverse plants such as extremophiles,
which are adapted to utmost environmental situations, can also provide a collection for stresstolerant
alleles. Hence, to obtain a more useful understanding of stress-tolerant characters
available in naturally occurring stress-resistant plants, further relative studies between the
present-day crops/model plants and crop progenitors/natural accessions/extremophiles are
needed.
Loss of stress tolerance during domestication
Domestication of crops by artificial selection often arises in differences to natural selection.
For example, farmers recommend the trait of non-shattering seeds, which is obviously a nonrecommendable
character for plants in nature that they require to propagate their offspring. The
breeding plans mostly target to evolve high yielding crop varieties. Thus, domestication has
outcome in growth of productivity but restricted genetic diversity, frequently by losing helpful
alleles such as stress-tolerant genes. During domestication procedure, useful characters can be
lost by gene loss, changes in gene regulation, and gene activity modification (i.e., sequence
variations in coding sequence).
Alleles for stress tolerance
Arabidopsis thaliana accessions (ecotypes) are largely dispersed to the different regions of the
world, and this dispersal contributes to the genetic diversity of Arabidopsis that are pivotal for
stress adaptation. Thus, genetic diversity among the Arabidopsis accessions give a helpful
genetic model to discover both unique stress tolerance mechanisms and important stresstolerant
alleles. For example, Jha et al. found a positive correlation between AtAVP1 transcript
levels and salinity tolerance. In comparison to Col and C24, the Ler and Ws accessions
exhibited higher transcript abundance of AtAVP1 in relation with higher salt stress tolerance.
In the first place, rice is a chilling-sensitive crop obtained from tropical or sub-tropical regions
of Asia. Rice cultivars comprises two subspecies, indica and japonica. When compared to
indica, the japonica rice cultivars were rated to be more cold-tolerant and grow at higher
altitudes and latitudes and temperate zones. Rice ecotypes include two major types, upland rice
and lowland rice. Lowland rice grows on flooded soils, while upland rice grows on dry soil;
therefore, upland rice cultivars are drought tolerant. In maize, the drought-responsive gene
ZmDREB2.7 shows natural variations in corporation with drought tolerance. The
Managing genetic resources for enhanced stress tolerance
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