High frequency plantlet regeneration in heat tolerant genotype of cauliflower (Brassica oleracea var. botrytis) and assessment of genetic fidelity by ISSR and SCoT markers

Cauliflower is an important cole crop, globally cultivated for its higly nutritious curd as well as its importance in human diet owing to medicinal properties. Cauliflower is a temperate vegetable grown in winter season, however, varieties suitable for off season cultivation are important to ensure its availability throughout the year and higher renumeration to farmers. Therefore, it is necessary to develop such off season high temperature stress tolerant varieties in cauliflower. A novel cauliflower genotype VRCF-75-1 is capable to produce good quality curds at very high temperature (38–45 °C Tmax and 25–32 °C Tmin) during the month of May and June and therefore, in the present study, regeneration protocol of this genotype has been developed for its rapid multiplication. Regeneration protocol involved sterilization of curd explants with 3% sodium hypochlorite which were subsequently evaluated for regeneration on MS media including modified vitamins supplemented with or without 6-benzyl amino purine (BAP), and zeatin (ZIA) 0.2 mg/L to 2.0 mg/L and 0.1 mg/L napthalene acetic acid (NAA). The maximum frequency of regeneration 75.56% was reported in media supplemented with 1.0 mg/L ZIA and 0.1 mg/L NAA. The genetic stability analysis by 12 ISSR and 7 SCoT markers on three randomly selected regenerated plantlets and mother plants showed no somaclonal variations in the regenerated plants. This is the first report for successful regeneration of high temperature tolerant cauliflower genotype that will ensure tissue culture based genetic improvement of cauliflower grown during summer season.