Sarmah, Bidyut KumarGogoi, Manab Bikash2024-06-262024-06-262023https://krishikosh.egranth.ac.in/handle/1/5810210919Bhimkol Musa balbisiana (Family Musaceae) under BB diploid genomic group (2n=2x=22) of banana is indigenous cultivar of Assam and has a traditional bond with the indigenous people of this region. Bhimkol is highly nutritious and possess medicinal properties. Fresh ripe pulp of the fruit has antiperoxidative and antioxidant properties which can prevent oxidative stress related diseases. Commercial importance of Bhimkol was realized with presence of industrial baby food products like Bhimvita, Bhim Shakti, Assam Bhim in the supermarket and online platforms like Amazon made from fresh fruit. The demand of ‘baby food product is increasing day by day not only in North eastern states but in other parts of India. However, presence of seed in the fruit is undesirable not only from consumption point of view but it impedes product development during industrial processing. Therefore, in the present study tissue culture methods towards development of seedless Bhimkol were studied. Male inflorescences were collected from orchards between 7-9 am to isolate anthers. Pollen viability test was conducted in bracts no 20 to 25 using 1% acetocarmine stain and highest percentage of viable pollen (78.16±15.32) was found in bract no 21. Microscopic study at 100x revealed the presence of uninucleate microspores along with dyad, triad and tetrad cells. Anthers containing uninucleate microspores were selected in the present study. In all, 300 number of anthers were inoculated in modified MS medium for callus induction. The highest frequency of friable androgenetic callus was observed after 60 days in modified MS medium supplemented with 2 mg/l of IAA and 1mg/l of 6-BAP. Calli were transferred in same medium for embryo germination. The germinated embryos were further treated with modified MS medium supplemented with IAA, BAP & CH for shoot induction. Growth regulators combination of 7 mg/l of BAP, 0.5 mg/l of IAA, 350 mg/l of CH was found to be the best for shoot induction and 12 numbers of plants were regenerated with a frequency of (4 %). Chromosome counting at metaphase stage revealed four (4) haploid n=11 with a frequency of (1.3%) and 8 diploids n=22 plants with a frequency of (2.66%). The ploidy level was reconfirmed by Flow Cytometer based on histogram florescence intensity associated with relative DNA content. For obtaining triploids endosperm culture was done using three types of explants 1) half cut seed, 2) endosperm and 3) endosperm containing zygotic embryo. Total 250 explants were inoculated in modified MS with different concentrations of growth hormones. Explants with half cut seed and endosperm degenerated after 28 days of inoculation due to blackening, whereas endosperm containing zygotic embryo produced white friable callus in modified MS mediim with 0.1 mg /l of 2, 4-D, 3mg/l of NAA and 0.5 mg kinetin. For shoot induction calli were transferred in different treatments of GR.Treatment no (T5) modified MS medium with 2 mg/l of NAA, 3 mg/l of BA produced the highest number of shoots regenerated and led to 26 numbers of plants. Chromosome counting, Flow cytometry test along with stomatal counts revealed 1 anueploid, 5 diploid and 20 triploids. Studies were also conducted to isolate protoplast from In vitro regenerated haploid and diploids tissue using reported protocol and demonstrated the regeneration of somatic hybrid through fusion of haploid and diploid protoplasts which was confirmed by histogram florescence intensity associated with relative DNA content using a Flow cytometer. The protocol for haploid, triploid and somatic hybridization could be used in future for increasing the frequency of haploid, triploid and somatic hybrids in order to develop seedless Bhimkol production.EnglishThesis