Effect of Different Concentrations of Auxin, as Well as Cytokinin on Callus Induction, Shoot Formation and Root Development in Pepino (Solanum Muricatum Ait. ) Cv. Valentia Under in- Vitro Condition

Abstract

ABSTRACT The pepino (Solanum muricatum Aiton), has been described as a succulent, juicy, and sweet fruit that is used mainly in desserts, although some cultivars have been used in salads due to their higher acidity content and grassy flavor notes. The pepino plant is a diploid (2n = 24) subtropical species and is also known as melon pear, melon shrub, or sweet cucumber. Native species from South America, It is conventionally propagated through vegetative means. But, this approach of propagation is not feasible for commercial production of plants and has at more time the chances of reduction yield. Therefore, the availability of quality planting material is of urgent need. Recently, there has been a promising approach for pepino multiplication at large scales through tissue culture because it generates a large number of contamination free plantlets in a minimum space and time. Use of mercuric Chloride (HgCl2 0.1%) + fungicide (Bavistin) (0.15%) for surface sterilization were found to be the best instead of their alone for higher explants survival after 10 days (83.23) per cent with low survival after 25 days (56.49) per cent treating for a period of 4.5 minutes with the treatment sodium hypocloride (70%) in established cultures. The earliest days taken for callus induction (27.32 days) was observed under 2-4 D 4.5ppm and maximum percentage (%) of explants callus formation after callus induction (66.86) per cent was noted under 2-4 D 4.5 ppm; while maximum volume of callus (24.99mm3) was observed in treatment 2,4-D 4.5ppm. Minimum days taken for shoot initiation (5.21 days) was noted under BAP 3.00 mgl-1 + IBA 0.50ppm, and minimum days taken for shoot development (40.82days) was noted under of BAP 3.00ppm + IBA 1.00ppm. The highest length of shoot (9.52cm) was produced in media supplemented with BAP 3.00 ppm + IBA 1.00ppm. Maximum percent of developed shoots obtained from the established culture (67.79) was noted under the treatment of BAP 3.00ppm + IBA 1.00ppm; While maximum shoots per explants/ inoculums from the established culture (4.06) was noted under the treatment of BAP 3.00ppm + IBA 1.00ppm. Maximum number of leaves / plantlet from the established culture (10.85) was noted under the treatment of BAP 3.00ppm + IBA 1.00ppm and maximum fresh weight (mg) of shoot / plantlet obtained from the established culture (26.05mg) was noted under the treatment of BAP 3.00ppm + IBA 1.00ppm. The established explants in the culture medium days taken for root initiation for pepino plant was minimum (6.84 days) was noted under IBA 3.00ppm + BAP 1.50ppm found significantly superior over all treatment and the least number of days taken for shoot development was observed (24.91) in the treatment IBA 3.00ppm + BAP 1.00ppm. The maximum percentage of root development (82.28) per cent was observed with concentration of IBA 3.0ppm and BAP 1.00ppm. Maximum root per plantlet obtained from the established culture (5.98) was found under the treatment of IBA 3.00ppm + BAP 1.00ppm and maximum development on length of root per plantlet (3.76 cm) respond to growth regulator supplemented with IBA 3.00ppm + BAP 1.00ppm; While maximum number of secondary roots/root obtained from the established culture (9.23) was found under the treatment of IBA 3.00ppm + BAP 1.00ppm