University of Kerala

Phytophthora foot rot, caused by Phytophthora capsici, remains a significant challenge in the cultivation of black pepper (Piper nigrum L.) worldwide. In this study, we analyzed the impact of P. capsici infection on photosynthetic efficiency and gas exchange in six elite black pepper genotypes under field conditions. By monitoring chlorophyll fluorescence and foliar gas exchange at 24, 48, and 72 h post-inoculation (hpi) of P. capsici, we observed significant disruptions in PSII function and key physiological processes. The fluorescence parameters, including F0, F0/Fm, Fv/Fm, ΦPSII, qP and qL, showed sensitive responses to infection, effectively distinguishing tolerant genotypes from susceptible ones. The genotypes IISR-Shakti—the only released genotype of black pepper for cultivation, designated as ‘moderately resistant’ against Phytophthora foot rot and Kuruvantherivalli—the high yielding traditional cultivar of the crop, demonstrated greater resilience by maintaining higher photochemical efficiency and stable gas exchange, while genotypes such as ‘PMM’- the only reported ‘lemon scented’ genotype of black pepper and Edamalayar-III—a wild genotype of the crop experienced notable decreases in Fv/Fm, ΦPSII, Pn, Ci, and E values. Correlation analysis revealed strong negative correlations between disease severity index (DSI) and these physiological traits. The results highlight the potential of chlorophyll fluorescence and gas exchange measurements as practical, non-invasive tools for early disease detection and screening. Notably, IISR-Shakti shows significant promise for breeding programs aimed at enhancing resistance to foot rot.

Climate change, primarily caused by rising greenhouse gas concentrations, is causing long-term changes in temperature, precipitation patterns, and extreme weather frequency, with far-reaching implications for agriculture and food security. Recent studies indicate that global staple crop yields have already declined by approximately 1.5% per decade due to climate-related stresses, highlighting the urgency for climate-resilient agricultural systems. Breeding programs must create climate-resilient cultivars in rapidly changing environments, while heat, drought, salinity, and increasing biotic stresses such as pests and diseases pose an increasing threat to crop productivity. Long growth cycles, little genetic diversity, and intricate genotype–environment interactions limit conventional plant breeding, despite its foundational nature. While current techniques like genomics-assisted selection, marker-assisted breeding, speed breeding, and genome editing are accelerating genetic advances, crop wild relatives and pre-breeding remain important sources of novel stress-tolerance genes. By combining these strategies, yield stability under climatic variability is supported and targeted improvements in biotic and abiotic stress tolerance are made possible. Future research must focus on breeding crops with tolerance to multiple simultaneous stresses, supported by high-throughput phenotyping platforms, artificial intelligence, and data-driven breeding approaches to enhance selection efficiency. In addition, strengthening global collaboration, conserving plant genetic resources, and promoting sustainable breeding strategies will be critical for ensuring long-term food security and climate-resilient agricultural systems. The most recent developments in climate-resilient crop breeding techniques are discussed in this review, which also emphasises integrated approaches for sustainable agricultural climate change adaptation.

Horticultural crops-including fruits, vegetables, ornamentals, spices, and plantation crops-are essential to global food security, human nutrition, and agricultural economies. However, their genetic improvement has long been constrained by biological complexities such as polyploidy, extended juvenile phases, vegetative propagation, and narrow elite germplasm pools. This review synthesizes breeding strategies across major horticultural crops, tracing the progression from classical phenotypic selection to molecular marker-assisted approaches and advanced genome editing technologies. Conventional breeding established the genetic foundation for crop improvement through hybridization, backcrossing, mutation breeding, and heterosis exploitation. The integration of molecular markers (RFLPs, SSRs, SNPs) with marker-assisted selection (MAS), quantitative trait locus (QTL) mapping, genome-wide association studies (GWAS), and genomic selection (GS) significantly enhanced breeding precision and efficiency. Advances in whole-genome sequencing, transcriptomics, metabolomics, and pan-genomics have further strengthened genomic resources for trait discovery and predictive breeding. More recently, CRISPR/Cas9 systems, including base editing and prime editing, have enabled precise targeted trait modification, demonstrated in applications such as extended shelf-life tomato, waxy-starch potato, Fusarium-resistant banana, and canker-resistant citrus. Despite these advances, challenges remain, including regulatory heterogeneity, transformation recalcitrance in elite genotypes, polyploid genome complexity, and public acceptance concerns. This review highlights critical research gaps and proposes an integrated breeding framework that combines classical genetics, genomic prediction, and precision genome editing to accelerate the development of climate-resilient, nutritionally enhanced, and commercially competitive horticultural crops.