bioRxiv Science⌕ Search

bioRxiv · 10.1101/2021.03.09.434553

Mapping of Quantitative Trait Locus (QTLs) that contribute to Drought Tolerance in a Recombinant Inbred Line Population of horsegram (Macrotyloma uniflorum)

Abstract

Horsegram (Macrotyloma uniflorum) is a drought hardy legume which can be grown in varied soil and temperature regime. It is an important food legume with environmental, nutritive and medicinal benefits. But in terms of genetic improvement it still lags behind other legumes. To get insight into the genetics of tolerance to drought stress, quantitative trait loci for drought tolerance traits were identified using an intraspecific mapping population comprising of 162 F8 Recombinant Inbred Lines derived from a cross between HPKM249 and HPK4. A total of 2011 markers were screened on parental lines for polymorphism survey, out of which 493 markers were found to be polymorphic and used for genotyping of the RIL population. Of these 493 polymorphic markers, 295 were assigned to ten linkage groups at LOD 3.5 spanning 1541.7cM with a mean distance of 5.20 cM between adjacent markers. This linkage map along with the phenotypic data for drought tolerance traits was used to identify regions of the horsegram genome in which the genes for the qualitative traits linked to drought tolerance located. A total of seven QTLs were identified for six different drought related traits. One QTL for malondialdehyde content on linkage group 2, two QTLs for root length on linkage group 3 & 9, one QTL each for proline content and chlorophyll content under drought stress on linkage group 4, one QTL each for root dry weight and root fresh weight on linkage group 5 were identified using composite interval mapping. The linkage map and identified QTLs will be utilized in Marker Assisted Breeding and increase our understanding on the physiology of drought stress tolerance. It will also aid in molecular breeding efforts for further genetic improvement of horsegram.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Katoch, M., Chahota, R.. 2021-03-09. Mapping of Quantitative Trait Locus (QTLs) that contribute to Drought Tolerance in a Recombinant Inbred Line Population of horsegram (Macrotyloma uniflorum). https://doi.org/10.1101/2021.03.09.434553

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Growth, yield, and quality of hot pepper (Capsicum annuum L.) as affected by the combined application of liquid bio-slurry and NPS fertilizer rates in Kucha, Gamo zone, south Ethiopia

Hot pepper (Capsicum annuum L.) is a key cash and nutritional crop in Ethiopia, yet its productivity remains constrained by inadequate and imbalanced soil nutrient management. Therefore, the field experiment was conducted in Kucha woreda, Gamo Zone, South Ethiopia, during the 2024/25 cropping season to investigate the effect of liquid bio-slurry and NPS fertilizer rates on growth, yield and quality of hot pepper. The experiment consisted of 16 treatments arranged in a factorial combination of four liquid bio-slurry (LBS) rates (0, 20, 40, and 60 m3 ha-1) and four NPS fertilizer rates (0, 75, 150, and 225 kg ha-1) using a randomized complete block design with three replications. All experimental data were collected following standard agronomic procedures and subjected to analysis of variance using GenStat statistical software (18th edition). The results revealed that both the main and interaction effects of liquid bio-slurry and NPS significantly (p < 0.01) influenced phenological, growth, yield, and quality parameters. The combined application of 150 kg ha-1 NPS and 60 m3 ha-1 LBS produced the highest marketable dry fruit yield (2.94 t ha-1) and total dry fruit yield (3.16 t ha-1), representing a 129.69% yield advantage over the control (1.28 t ha-1) in the case of marketable dry fruit yield. The findings demonstrate that integrated nutrient management using combined LBS and NPS fertilizers significantly enhanced the productivity and quality of hot pepper. Therefore, the application of 150 kg ha-1 NPS combined with 60 m3 ha-1 liquid bio-slurry is recommended for improved hot pepper production for the study area and similar agro-ecological conditions.

plant biology↗

Robust planar morphogenesis in leaf-like organs requires callose-dependent coordination of division and growth

Planar organs, such as leaves, are key developmental innovations underlying the evolutionary success of plants. In vascular plants, building a planar organ requires coordinating cell division and growth both within the organ plane and across multiple, mechanically distinct cell layers. Phyllids, the leaf-like organs of bryophytes, typically consist of a single cell layer and offer a minimal system to decouple in-plane growth coordination from inter-layer mechanics. Here, we investigate how robust planar morphogenesis is achieved in phyllids, using the moss Physcomitrium patens as a bryophyte model. We show that impaired cytokinesis, caused by the loss of a callose synthase gene, disrupts growth gradients, ultimately yielding smaller, non-planar organs of variable shape. Combining quantitative live imaging with computational modeling, we show that the severity of shape defects in mutants depends on the spatial distribution and developmental timing of local growth arrests. These findings reveal how callose-dependent coordination between cell division and in-plane growth prevents mechanical conflicts and maintains planarity in a monolayered plant organ.

plant biology↗

Structural determinants underlie the essentiality of the m-type thioredoxin TrxA in Synechocystis

Thioredoxins are central regulators of thiol-based redox signaling in photosynthetic organisms, where multiple isoforms with partially overlapping functions coexist. Among them, TrxA is the cyanobacterial homolog of chloroplast m-type thioredoxins and the only thioredoxin known to be essential in cyanobacteria. However, it is unclear whether this essentiality is due to its high intracellular abundance or to its specific molecular properties. Here, we evaluated the ability of different thioredoxins to functionally replace TrxA and used TrxA/TrxB chimeras to identify the structural determinants underlying its functional specificity. Overexpression of TrxB, TrxQ or TrxC did not support complete segregation of a disrupted trxA locus, although the proteins accumulated to levels comparable to those of endogenous TrxA. Similarly, heterologous expression of NTRC did not rescue the phenotype associated with reduced TrxA levels. Comparative structural analysis revealed differences in surface electrostatics and structural features surrounding the catalytic site of TrxA compared with the other thioredoxins. Analysis of TrxB/TrxA chimeras showed that determinants required for functional complementation are primarily located within the C-terminal region of TrxA. Chimeric variants also differed in their ability to activate cyanobacterial FBP/SBPase and pea chloroplast FBPase in vitro, supporting a role for this region in target-specific interactions. Together, these results demonstrate that the essential function of TrxA cannot be explained by protein abundance alone and requires molecular determinants located primarily within its C-terminal region.

plant biology↗