The slow breeding cycle presents a significant challenge in legume research and breeding. While current speed breeding (SB) methods promise faster plant turnover, they encounter space limitations and high costs. Enclosed environments risk pest and disease outbreaks, and supplying water and electricity remains challenging in many developing nations. Here, we propose an innovative natural speed breeding (nSB) approach to achieve two generation cycles per rabi season under natural open field conditions in chickpea. This cost-effective, environmentally friendly method offers a location-specific alternative to prevalent SB techniques. Two field experiments were conducted. First, 11-day-old fresh immature green (FIG) seeds exhibited an 80% germination rate, reducing the duration of the breeding cycle by 14%. In second, abiotic stresses such as atmospheric, nutrient, soil, and water stresses reduced the duration of the breeding cycle by 40%, 18%, 15%, and 18%, respectively. Despite the shortened generation time, we consistently obtained a minimum of 4–6 pods plant-1, ensuring continuity in the subsequent breeding cycle without compromising the nSB process. Our investigation revealed that the combination of this location advantage (40%) with the sowing of FIG seeds (14%) enables Baramati to achieve progress from F2 to F5 in 1.5 years, with two generation cycles per rabi (cool) season. Using the nSB method can save 3 years, marking a notable reduction from the conventional six-year timeline. Moreover, incorporating the additional abiotic stresses mentioned above will further reduce the generation advancement time. Therefore, nSB accelerates generation turnover and reduces varietal improvement time at a low cost.

Pulses are inherently climate-resilient crops by virtue of their special morphophysiological attributes, such as deep tap root system, higher water-use efficiency, nitrogen-fixing ability, ability to host beneficial microbes in the rhizosphere to solubilize phosphates, etc. Low water and nutrient requirements, nitrogen-fixation ability, and high proteins are the prominent features of pulses that discriminate them from other crops. Besides having the potential to increase soil fertility, the seeds of pulses are densely packed with nutrients. Being rainfed crops, pulses often experience terminal drought and heat stress at reproductive stages. The majority of the pulses are sensitive to high temperature above 35°C, leading to inhibition of photosynthesis and reduction of pollen fertility. Improving water relation characteristics could be one of the best strategies to addresses combined drought and heat tolerances. Deep root, osmotic adjustment, lower ¹³C/¹²C carbon isotope discrimination ratio, and lower stomatal aperture contribute significantly toward improving water-use efficiency, although cellular-level tolerance, including expression of antioxidative enzymes, heat shock proteins, acquired thermotolerance, membrane stability, and altered carbohydrate metabolizing enzymes, play important roles toward dual tolerance. However, the primary strategy of pulses to acquire tolerance could be by means of improved water relation characteristics. Faster biomass accumulation, early flowering, deep roots, and regulated transpiration water loss through modified stomatal morphology have direct ways of conserving moisture and cellular-level tolerance have further additive advantages toward combined tolerance. Pulses should be acquired with adequate photothermoinsensitivity and introgressed with cellular-level tolerance to stabilize yield. Based on precision phenotyping, such as chlorophyll fluorescence, antioxidative enzymes, photosynthesis, osmotic adjustment, root profile, acquired thermotolerance, and water-use efficiency, a number of pulse germplasms have been identified as tolerant to various abiotic stresses. Field-level screening, including thermal imaging, NDVI, and SPAD chlorophyll readings, are available at the first level of selection against drought or heat. Major pulses, such as chickpea, pigeonpea, lentil, and lathyrus, are relatively drought tolerant as compared to greengram, blackgram, and fieldpea. Wild species of these pulses are the house of many abiotic stress-tolerance genes. Genetic diversity of abiotic stress tolerance can be exploited by using precision phenotyping. Genomics, transcriptomics, epigenomics, proteomics, metabolomics, and phenomics tools have enabled speeding up breeding programs more precisely.

Chickpea is a cool season, photothermal-sensitive crop, that is adversely affected by high temperatures (>35°C) and whose flowering is promoted by long-day conditions (>12 h). This prevents horizontal crop spread under a variety of agro-climatic conditions and the development of insensitive genotypes that perform well in all seasons. Therefore, a study was conducted to identify genotypes that are mature early, insensitive to photoperiod, high temperature and tolerant to drought stress. A set of 74 genotypes was evaluated under rainfed conditions in Kharif 2021 (off-season) to select eight promising early-maturing genotypes with high-yielding capacity. Then further investigations were conducted in five different seasons Late Kharif 2021, rabi 2021, summer 2022, early Kharif 2022 and Kharif 2022 to identify the genotypes with photothermo-insensitivity among the selected eight genotypes. With the exception of rabi 2021, each of these seasons were distinct from the chickpea's typical growing season. Among these eight, the stable genotypes which are performed better in all the seasons, especially in summer were considered, such as IPC 06-11, MNK-1, JG-14 and ICE 15654-A as a photothermo-insensitive, were able to flower and set pods with higher seed yield and, resulting in early maturity in a temperature range of 41.4/9.3°C with photoperiods of 13.1/10.9 h to reach in all seasons throughout the year. The heritability was more than 60%. Hence, these genotypes can be used as donor aids in the development of early maturing, drought stress tolerant and photothermo-insensitive chickpea.