Genetic Mechanisms for Hybrid Breeding in Vegetable Crops.

To address the complex challenges faced by our planet such as rapidly changing climate patterns, food and nutritional insecurities, and the escalating world population, the development of hybrid vegetable crops is imperative. Vegetable hybrids could effectively mitigate the above-mentioned fundamental challenges in numerous countries. Utilizing genetic mechanisms to create hybrids not only reduces costs but also holds significant practical implications, particularly in streamlining hybrid seed production. These mechanisms encompass self-incompatibility (SI), male sterility, and gynoecism. The present comprehensive review is primarily focused on the elucidation of fundamental processes associated with floral characteristics, the genetic regulation of floral traits, pollen biology, and development. Specific attention is given to the mechanisms for masculinizing and feminizing cucurbits to facilitate hybrid seed production as well as the hybridization approaches used in the biofortification of vegetable crops. Furthermore, this review provides valuable insights into recent biotechnological advancements and their future utilization for developing the genetic systems of major vegetable crops.

Genome editing for vegetable crop improvement: Challenges and future prospects.

Vegetable crops are known as protective foods due to their potential role in a balanced human diet, especially for vegetarians as they are a rich source of vitamins and minerals along with dietary fibers. Many biotic and abiotic stresses threaten the crop growth, yield and quality of these crops. These crops are annual, biennial and perennial in breeding behavior. Traditional breeding strategies pose many challenges in improving economic crop traits. As in most of the cases the large number of backcrosses and stringent selection pressure is required for the introgression of the useful traits into the germplasm, which is time and labour-intensive process. Plant scientists have improved economic traits like yield, quality, biotic stress resistance, abiotic stress tolerance, and improved nutritional quality of crops more precisely and accurately through the use of the revolutionary breeding method known as clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 (Cas9). The high mutation efficiency, less off-target consequences and simplicity of this technique has made it possible to attain novel germplasm resources through gene-directed mutation. It facilitates mutagenic response even in complicated genomes which are difficult to breed using traditional approaches. The revelation of functions of important genes with the advancement of whole-genome sequencing has facilitated the CRISPR-Cas9 editing to mutate the desired target genes. This technology speeds up the creation of new germplasm resources having better agro-economical traits. This review entails a detailed description of CRISPR-Cas9 gene editing technology along with its potential applications in olericulture, challenges faced and future prospects.

Generation of doubled haploids in cauliflower.

Hybrids of cauliflower are in high demand world over due to their high yield potential, earliness, better quality, better resistance to biotic and abiotic stresses. Conventionally, hybrids are developed from the intercrossing of two diverse inbred parental lines which are developed through continuous inbreeding for 8-10 generations and still don't attain complete homozygosity. Doubled haploid technology on the other hand generate completely homozygous inbred lines in a single step. Therefore, a study was undertaken at Punjab Agricultural University, Ludhiana, to develop a protocol for the development of doubled haploid lines in cauliflower. The anthers were excised from the flower buds of different genotypes viz. Jyoti, Pusa Sharad, Kartiki, CAUMH-2, CAUMH-10, LS-2, LS-3, and LS-5 followed by their culture on five different callus induction media compositions. Genotypes differed significantly in the ability to induce callus which was maximum in Jyoti followed by LS-2. Different media compositions also varied significantly in callus induction efficiency which was maximum on MS media+1.5 mg/L 2,4-D +1.0 mg/L NAA. Maximum shoot regeneration was recorded in genotype Kartiki followed by LS-2 when cultured on MS media+3.0 mg/L BAP+2.0 mg/L Kin. The regenerated shoots thus obtained were rooted on ½ MS media +1.0 mg/L IBA. Ploidy analysis of root tips revealed that 22.2% of the regenerated plantlets were haploids, 27.8% were spontaneous doubled haploids, 16.7% were tetraploids and remaining 33.3% were mixoploids.