Background: Chickpea is one of the major legume crops being cultivated in the arid and semi-arid regions of Pakistan. It is mainly grown on the marginal areas where, terminal drought stress is one of the serious threats to its productivity. For defining the appropriate selection criteria for screening drought tolerant chickpea genotypes, present study was conducted. Distinct chickpea germplasm was collected from different pulses breeding institutes of Pakistan and evaluated for drought tolerance at germination and early seedling stages, furthermore, at late vegetative growth stages physiochemical traits and multi-environment yield performance were also tested. Results: Chickpea genotypes under different environments, were significantly varied for different seedling traits, physio-chemical attributes and seed yield. Genotypes showing drought tolerance by performing better at an early seedling stages were not correspondingly high yielding. Screening for drought tolerance on seed yield basis is the most appropriate trait to develop the drought tolerant as well as high yielding chickpea genotypes. Results confirmed that traits of early growth stages were not reflecting the drought tolerance at terminal growth stages and also did not confer high yielding. NIAB-rain fed environment proved ideal in nature to screen the chickpea genotypes whereas, NIAB-lysimeter and Kalur Kot was least effective for selecting genotypes with high seed yield. Genotypes D0091–10, K010–10, D0085–10, K005–10, D0078–10, 08AG016, 08AG004, D0080–10, 09AG002, K002–10 and D0099–10 were high yielding and drought tolerant based on their performance across multiple hotspot environments. Conclusions: The selected genotypes are intended for further evaluation for varietal approval to recommend for general cultivation on farmer fields in drought hit areas of Pakistan. Among physio-biochemical traits, higher proline, glycine betain, RWC and CMS were reflecting the higher capability to tolerate the drought stress in chickpea. Drought sensitive genotypes (K0037–10, 2204, K0052–10, 09AG015, K0042–10, CM709/06, K0068–10, K004–10, K0026–10 and K0063–10) were also identified in present study which were resourceful asset for using as contrasting parents in hybridization programs. To our knowledge, this is first report using an integrated approach involving, physio-biochemical indices, and multi-environmental yield trials, for comparison, screening and selection of chickpea genotypes for drought tolerance.

The incidence of short episodes of high temperature in the most productive rice growing region is a severe threat for sustainable rice production. Screening for heat tolerance and breeding to increase the heat tolerance of rice is major objective in the situation of recent climate change. Replacing sensitive genotypes with heat tolerant cultivars, modification in sowing time, and use of growth regulators are some of the adaptive strategies for the mitigation of yield reduction by climate change. Different strategies could be adopted to enhance the thermos-tolerance of rice by (1) the modification of agronomic practices i.e., adjusting sowing time or selecting early morning flowering cultivars; (2) induction of acclimation by using growth regulators and fertilizers; (3) selecting the genetically heat resistant cultivars by breeding; and, (4) developing genetic modification. Understanding the differences among the genotypes could be exploited for the identification of traits that are responsible for thermo-tolerance for breeding purpose. The selection of cultivars that flowers in early morning before the increase of temperature, and having larger anthers with long basal pore, higher basal dehiscence, and pollen viability could induce higher thermo-tolerance. Furthermore, the high expression of heat shock proteins could impart thermo-tolerance by protecting structural proteins and enzymes. Thus, these traits could be considered for breeding programs to develop resistant cultivars under a changing climate.

Drought and heat are major abiotic stresses that usually occur simultaneously and cause significant yield losses in cereal crops including maize (Zea mays L.). First, ten genotypes of maize were screened using root length stress tolerance indices under heat (40 °C for 2, 4 and 6 h) and drought (-0.2, -0.4, and -0.6 MPa) stress. Two tolerant and two sensitive genotypes were selected and their growth and different biochemical traits were analyzed under drought stress (60% field capacity), heat stress (one cycle of 40 °C for 6 hours) and combined drought and heat stress. The results showed that drought stress had a predominant effect over heat stress, whereas combined drought and heat stress caused significant adverse effects on all parameters. The biochemical attributes such as total soluble sugars (TSS), proline, and total free amino acids (TFAA) were increased, whereas total soluble proteins (TSP) and nitrate reductase activity were decreased as compared to controls under all stress treatments. Biomass was positively correlated with the transpiration rate and TSP, while negatively related to leaf temperature and TFAA. The tolerant genotypes maintained higher proline, TSP, TSS, and TFAA contents and could be used for breeding for the adaptation to drought and heat under climate change.

Soil salinity is a serious abiotic factor affecting the production of crops by reducing potassium (K) uptake due to strong competition with sodium (Na) cations in the root regions. In calcareous soils, most of the nutrients precipitate in unavailable forms for plants. This study investigated the physiological and biochemical response of two wheat genotypes salt tolerant Abadghar and salt sensitive Pari-73 supplemented with K and zinc (Zn) nutrition. A factorial experiment with three levels of K (0, 50 and 100 kg ha⁻¹) and three levels of Zn (0, 25 and 50 kg ha⁻¹) based on a complete randomized design was employed. The results showed significant effect of treatments on chlorophyll (Chl) contents, water relations, nitrogen metabolism and yield attributes. The treatment K+Zn (100, 25 kg ha⁻¹) was the most effective in increasing grain yield. The results achieved highlight the importance of K and Zn nutrition in salt-stress conditions.