<div>Background: Freezing temperatures are a limiting factor hindering the survival of alfalfa (Medicago sativa L.) through winter. Soil drought also damages alfalfa crowns and can affect their regeneration. Therefore, it is important to determine the effects of cold, dry conditions on alfalfa to develop effective water management strategies in winter. 
 
Methods: Cold, dry conditions were established in the laboratory and the freezing tolerance of crowns was compared between the alfalfa cultivars &lsquo;WL440HQ&rsquo; and &lsquo;ZhaoDong&rsquo;. The degree of freezing tolerance was estimated on the basis of relative electrolyte leakage and semi-lethal temperature. The effects of cold, dry conditions on alfalfa crowns were determined by investigating the rate of water loss and the concentrations of soluble sugars (which function as cryoprotectants) and betaine and proline (which function as osmoregulation substances).&nbsp; 
 
Result: Compared with crowns of &lsquo;ZhaoDong&rsquo;, those of &lsquo;WL440HQ&rsquo; showed a higher water loss rate in cold, dry conditions and were irreversibly damaged and their freezing tolerance was severely affected. In comparison, crowns from &lsquo;ZhaoDong&rsquo; showed a lower water loss rate and lower relative electrolyte leakage under cold, dry conditions and their freezing tolerance was not significantly affected. The higher water loss rate and lower freezing tolerance were the direct causes of death of &lsquo;WL440HQ&rsquo;, the cultivar with a higher fall dormancy score. In cold, dry conditions, the content of proline, an osmotic regulation substance, increased in response to soil water deficit and may have improved the ability to withstand freezing temperatures by preventing rapid water loss. In addition, sucrose, fructose, galactose and stachyose contents in the crown increased under cold, dry conditions and may have enhanced freezing tolerance because of their function as cryoprotectants. The results of this study indicate that maintaining soil moisture within the range suitable for the growth of crowns is important for the successful overwintering of alfalfa.</div>

Role of Osmotic Regulation and Cryoprotectant Substances in the Freezing Tolerance of Alfalfa in Cold, Dry Conditions

Background: The cold stress adversely affects the growth, survival and reproductive capacity of plants if the minimum temperature falls below 5&deg;C. Information&rsquo;s regarding cold stress and its impact on morphological characters, physio-biochemical constituents and yield attributes in cold tolerant and susceptible pigeon pea genotypes are very limited. Keeping the above facts in to consideration, the experiments were conducted. 
 
Methods: Field experiments were conducted during 2018-19 and 2019-20 with 34 genotypes of pigeon pea including checks (NDA-1, Bahar, IPA203, NDA-2, MAL-13, ICP2275, IPACT-2, MA-6, IPACT-3, IPACT-24, Rajendra Arhar, IPA15F, Dholi-D, JBT46/27, IPACT-6, IPACT-14, IPAD1-17, IPAC 68, IPACT 22, ICPL 7035 IPA19-101, IPA19-102, IPA19-103, IPA19-104, IPA19-105, IPA19-106, IPA19-107, IPA19-108, IPA19-109, IPA19-110, IPA19-111, IPA19-112, IPA19-113, IPA19-114) in RBD at ICAR-IIPR, Kanpur. Morphological and yield Characters including plant height, scoring of cold injury in exposed plants and Number of flower drop and pod set during the cold period in tagged plants were recorded. In biochemical/ crop efficiency parameters viz: Nitrogen balance index, chlorophyll, flavonols, anthocyanin&rsquo;s and NDVI were measured. The photosynthetic rate, stomatal conductance, and transpiration rate were measured at the pod formation stage. Anti-oxidant enzymes activity was assayed as per standard methods. Meteorological observations during Cold stress were recorded. 
 
Result: Based on flower/pod drop and retention the genotypes like IPA 15F, Dholi dwarf, JBT46/27, IPACT-6, IPACT-14, IPAC-1-17, IPACT-68, IPACT-22, IPA 19-101, IPA 19-102, IPA 19-103, IPA 19-104, IPA 19-105, IPA 19-107, IPA 19-108, IPA 19-109, IPA 19-110, IPA 19-111 and IPA 19-113 were found susceptible to cold stress and retaining an average 51.67 % flowers/pods. Genotypes like NDA-2, MAL-13, ICP2275, IPACT-2, MA-6, IPACT-3, IPACT-24, Rajendra arhar, IPA19-106, IPA19-112 and IPA19-114 have retained more than an average of 67.48% flowers/pods are considered tolerant to cold stress. Amongst the tolerant group NDA-2, MAL-13, ICP2275, IPACT-2, IPA19-106, IPA19-112 retained the flower/pod more than the average of check genotypes (67.57%).&nbsp; Biochemical/plant efficiency parameters were superior in tolerant group over susceptible group.

Physiological Characterization of Cold Tolerant and Susceptible Pigeon Pea [Cajanus cajan (L.) Millsp.] Genotypes

<div style="text-align: justify;">The experiments concluded 48hrs for germination testing as most appropriate stress duration. Using paper roll for recording the traits was the best method than petri dish and towel method. Among the traits relative germination rate (RGR), relative seedling length (RSL), relative root length (RRL), relative root fresh weight (RRFW) and relative root dry weight (RRDW) were proved to be flooding-responsive. RSL was chosen as the major seed-flooding indicator due to higher heritability (h2), genotypic coefficient of variation (GCV), correlation with other indicators and easier measuring procedure, while RRL was considered as the subsidiary indicator. Thus, the RSL in paper roll after 48hrs seed-flooding was recognized as standard seed-flooding testing procedure and used to evaluate breeding materials. Among the 11 cultivars, the superior seed-flooding-tolerant ones were M8206, NN1138-2 and ZXD, while ten best lines were evaluated from one hundred breeding lines.</div>

Establishment of evaluation procedure for soybean seed-flooding tolerance and its application to screening for tolerant germplasm sources&nbsp;

Background: Bottle gourd, a popular winter vegetable in Bangladesh, is experiencing a year-round increase in demand. High temperature stress disrupts physiological structure, fruit quality and crop yields, limiting the year-round cultivation of bottle gourd. The research aimed to identify heat stress-tolerant genotypes to extend growing seasons and increase production among varieties and breeding materials. 
 
Methods: The study conducted at Vegetable Research Center, Dinajpur of BRAC Seed and Agro Enterprise, Bangladesh consisting 58 bottle gourd genotypes under normal and heat stress conditions using augmented block design. Meteorological data showed heat stress resulted ~5-7oC higher air temperatures than normal sowing environments. 
 
Result: Heat stress tolerance indices indicated that the genotypes with a combination of greater values of MP, GMP, HM, YI and STI and lower values of SSI and TOL are high performed and productive breeding material. Yield based stress indices SSI and TOL had a negative association with fruit yield under heat stress (Ys), while strong positive correlations with STI, MP, GMP, HM and YI. The cluster analysis classified bottle gourd genotypes as tolerant, medium tolerant and susceptible to heat stress. Heat stress tolerance indices could be effective tools for identifying heat tolerant bottle gourd genotypes in field. The genotypes BG-45, BG-02, BG-57, BG-39 and BG-43 determined as high performing and stable breeding material under both normal and heat stress environments and might potentially be employed in future breeding programs.

Heat Stress Tolerance Indices and Their Contribution in Identifying Heat Tolerant Bottle Gourd [Lagenaria siceraria (Molina) Standl.] Genotypes

Background: Chickpea is a globally important commercial crop and a key source of protein for vegetarian populations. Though chickpea was domesticated at least 3000 years ago, research into abiotic stress tolerance has been limited compared to cereals.&nbsp; 
 
Methods: An experiment was conducted with a set of seventy-one genotypes of Desi chickpea (Cicer arietinum L.) to isolate high temperature tolerant genotypes using randomized block design (RBD) under two different sowing conditions (normal and late/terminal heat stress) and two growing seasons (rabi-2017-18 and 2018-19) at the Pulses Research Station of Junagadh Agricultural University. The screening of heat tolerant genotypes was done based on nine morpho-phenological traits, stress tolerance indices and correlation amongst them.&nbsp; 
 
Result: The heat tolerant genotypes of chickpea had less percentage of reduction in numbers of pods, seed yield per plant and 100-seeds weight. Five genotypes viz., ICC 4958, ICC 14595, ICC 8318, GG 4 and ICCV 92944 were identified as highly heat tolerant on the basis of HSI and YSR. These tolerant genotypes and screening criteria&rsquo;s can be of great importance to identify donor parents to develop new cultivars for the farmers growing chickpea in the heat prone regions.

Evaluation of Desi Chickpea (Cicer arientinum L.) Landraces for Heat Tolerance using Morpho-phenological Traits and Stress Tolerance Indices (STI)

Background: Soybean [Glycine max (L.) Merrill], popularly known as the &ldquo;Golden bean,&rdquo; is a major oilseed crop valued for its high protein and oil content. Soil salinity is a critical abiotic stress that adversely affects germination, growth and productivity in soybean. Identifying salinity-tolerant genotypes remains a key challenge for breeders and seed technologists. Therefore, standardized and reliable screening protocols are essential for the rapid identification of salinity-tolerant genotypes. 
 
Methods: The study was conducted at ICAR-IARI, New Delhi, during the kharif season of 2022 and 2023. A total of 156 soybean genotypes were evaluated, including 150 germplasm accessions (42 black-seeded, 105 yellow-seeded and 3 brown-seeded) with one-year-old stored seeds and six freshly harvested yellow-seeded varieties. Two techniques, namely the top-of-paper method and the between-paper method, were assessed. The top-of-paper method, with application of 2.5 ml NaCl solution on alternate days, was selected as a standard method. Salinity stress was imposed using four NaCl concentrations (0, 3, 6 and 9 dS/m) and seed quality traits [germination, seedling length, fresh and dry weight, Seedling Vigour Indices (SVI-I, SVI-II)] were integrated with the Salt Tolerance Index (STI) for genotypic categorisation. 
 
Result: Significant genotypic variation was observed for seed germination and seed quality under salinity stress. Black-seeded accessions and freshly harvested varieties showed higher germination and vigour than yellow-seeded accessions, which were poor storers. STI correlated positively with vigour indices at 6 dS/m in black accessions and released varieties and at 3 dS/m in yellow accessions. Brown-seeded accessions showed inconsistent responses. Based on STI and correlation, 20 genotypes were categorised as highly tolerant, moderately tolerant, or susceptible. Principal Component Analysis (PCA) identified seedling length and dry weight as key contributors to variation, while MGIDI analysis improved the efficiency of multivariate selection, identifying superior genotypes under both control and stress.The integration of physiological parameters with the Salt Tolerance Index (STI) served as an effective screening method for categorising genotypes into tolerant and susceptible groups. These findingshighlight the importance of using a reliable screening protocol using STI for successful soybean cultivation under salinity stress conditions. 
&nbsp; 
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Integrating Seed Quality Traits and Salt Tolerance Indices for Efficient Screening of Salinity-Tolerant Soybean [Glycine max (L.) Merrill] Genotypes

<div>Background: Peanut is a widely cultivated food crop of the legume family and is a major source of vegetable oil and protein in the global agricultural economy. However, the productivity of peanuts is severely affected by abiotic stress, particularly drought. Therefore, it is necessary to identify genes related to abiotic stress tolerance and analyze genetic diversity by SSR markers related to drought tolerance in peanut varieties. 
 
Methods: PCR amplification was used for the isolation of the DREB2C gene. The DREB2C gene sequence was analyzed using bioinformatic tools to identify functional domains, 3D modeling structures and other important characteristics. RT-qPCR was performed to evaluate the expression level of the DREB2C gene in the different tissues of peanut cultivars. A phylogenetic tree was constructed based on SSR markers linked to drought tolerance to assess the genetic diversity among peanut cultivars. 
 
Result:&nbsp;The present study identified the DREB2C gene in peanut cultivar L14. The gene encodes a polypeptide chain of 492 amino acids lacking transmembrane domains and signal peptides and with a conserved domain (AP2/ERF) and DNA binding site. The 3D protein structure was predicted with high confidence using various tools. The gene expression was investigated in different tissues and at different growth and developmental stages, as well as in various cultivars. Based on SSR markers linked to drought tolerance, the study revealed that peanut cultivars in Vietnam exhibit a medium level of diversity. It may be suggested that cross-breeding between different groups may increase variability among crops, allowing the generation of dominant varieties with improved drought tolerance.</div>

Identification and Characterization of the DREB2C Drought-tolerant Gene in Peanut Cultivar L14 and Genetic Diversity Assessment of Some Peanut Cultivars based on SSR Markers Linked to Drought Tolerance

<div>Background: In north India, pigeon pea experiences low temperature stress during winter months (December-January). Information&rsquo;s regarding cold stress and its impact on morphological characters, physio-biochemical processes and yield attributes in pigeon pea crop is very limited. Keeping the above facts in to consideration, the experiment was formulated to screen suitable genotypes of pigeon pea tolerant to cold stress based on morpho-physiological traits and ability to set flower and pods and yield performance.&nbsp;&nbsp; 
 
Methods: Field experiments with 98 genotypes of pigeon pea were conducted in augmented design including checks with all recommended cultural practices in 2018-19 and 2019-20 at New Research Farm, ICAR-IIPR, Kanpur. Morphological, biochemical and yield parameters were recoded periodically.&nbsp; 
 
Result:&nbsp;Based on the reaction of pigeon pea genotypes against the exposer of cold stress in terms of flower/pod drop and flower/pod retention, cold injury at the apical meristems and post regeneration of apical portion, the genotypes like IPA 15F, Dhule-D, JBT46/27, IPACT-6, IPACT-14, IPAC-1-17, IPACT-68, IPACT-22 showed &gt;90% flower/pod drop and retained only 0-10% flowers/pods, &gt;90% apical damage and &lt;10% recovery of apical portion and were considered highly sensitive to cold stress. Genotypes namely MA-3, IPA 9F, ICP 15-9-1, VKG 27/161, H-26, ICPL 7035, LRG-30, PBT/SSL 2/73, KPL 1034-31, IPA 15-15, KPL 34, ICP 2073, IPACT-5, IPAB 10-66, IPACT-10, IPACT-11, IPAHT-26, IPACT-15, IPAD 2-8, IPACT-16, IPAD-8, IPACT-17, IPAHT-43, IPACT-21 showed &gt;80% flower/pod drop and retained 10-20% flower/pods, &gt;80%apical damage and &lt;20% recovery of apical portion and considered moderately susceptible to cold stress. Genotypes NDA-2, MAL-13, ICP-2275, IPACT-2 showed around 20-40% flower/pod drop and have retained 60-80% flowers/pods, &lt;20% apical damage and&gt;80% recovery of apical portion were considered as the highly tolerant to cold stress. The nitrogen balance index, chlorophyll and flavonols showed higher values in tolerant group whereas lower in susceptible group. The average yield/plant of pigeon pea genotypes tolerant to cold stress is considerably higher than the susceptible group of pigeon pea genotypes.</div>

​Performance of Pigeon Pea [Cajanus cajan (L.) Millsp] Genotypes under Cold Stress

<div>In order to meet the challenges of providing food to the ever increasing population of the world, there is an insistent need to boost crop yield. Unfortunately, the production of agriculture decreasing due to various environmental factors including frost and cold are very important, especially in winter. Indeed, frost is the most important abiotic problem and one of the doctrine limiting factors affecting plant growth and development in winter. Despite various obvious symptoms under frost stress, the yellowing of leaves, weak germination, curling of leaves, decreased rate of cell swelling and wilting, reduced flower opening, curling of petals leads to the cells death. This severe damage is largely due to the sensitive drying associated with freezing during frost. In addition, signal transduction is to switch on frost response genes and transcription factors to mediating stress tolerance, thus underline mechanism of frost stress and genes involve in the frost/cold stress signal network is very important for plant growth and development. In present review, plant significances in daily life and issues related to abiotic stresses such as frost and cold tolerance mechanisms are discussed.</div>

<div>Frost Stress Tolerances and Cut Roses: A Review</div>

Background: Alfalfa (Medicago sativa L.), a vital forage crop, demonstrates pronounced variability in growth performance and yield in cold regions, largely determined by its cold tolerance. Fall dormancy ratings, a key indicator of alfalfa&rsquo;s winter dormancy intensity, induce distinct physiological responses and cold tolerance capacities among varieties under low-temperature stress. Therefore, investigating the germination traits and seedling physiological adaptations of alfalfa with varying fall dormancy ratings under cold stress is critical for breeding and cultivating cold-tolerant alfalfa cultivars. 
 
Methods: This experiment was conducted in the Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, from March to September 2024. A total of 28 alfalfa materials with 10 different fall dormancy grades were used. Low-temperature stress experiments were conducted to evaluate critical germination parameters, including germination rate, germination index, vigor index, root length and germination coefficient. Concurrently, seedling physiological responses were investigated under 4oC conditions, focusing on biochemical markers: Malondialdehyde (MDA) content, relative conductivity (REC) and the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), along with proline (Pro) and soluble sugar (SS) accumulation. 
 
Result: Under low-temperature stress, significant reductions were observed in germination parameters, including germination rate, germination index, vigor index, root length and germination coefficient, across alfalfa accessions of different fall dormancy ratings. A strong negative correlation was established between fall dormancy ratings and cold hardiness during germination. Physiological analysis revealed that key biochemical markers-MDA, REC, SOD, POD, CAT, Pro and SS-under 4oC stress conditions. Accessions with lower fall dormancy ratings demonstrated superior cold hardiness, while those with higher fall dormancy ratings showed reduced tolerance. Through comprehensive analysis, REC, SOD, POD and SS were identified as the most critical physiological indicators for evaluating cold hardiness at the seedling stage.