Standardization of In-Vitro Protocol for Mass Multiplication of Date Palm Cultivars Halawy and Khalas

Abstract

The date palm (Phoenix dactylifera) is one of the oldest fruit plants grown for its delicious fruit with high energy value. The plants can tolerate extremes of temperature and saline conditions of arid region. Therefore, in Thar dessert of Rajasthan and Kutch region of Gujarat several varieties were introduced and evaluated in our country, which have shown promising response. However, availability of quality planting material is one of the major limiting constraints in its area expansion programme. So far, it is multiplied by off-shoots which are cumbersome and not an efficient method of date palm multiplication. Some organizations have made efforts to develop in-vitro protocol but it is variety specific and demands for planting materials of commercial varieties are huge. Government is also supporting to import the tissue culture planting material which is very expensive. Therefore, alternative seems to be have our own protocol for mass multiplication of commercial varieties of date palm. In view of above, the present investigation was carried out in the Biotechnology Laboratory of ICAR-Central Institute for Arid Horticulture, Bikaner during 2017-18. The somatic embryos of date palm cultivars Halawy and Khalas were inoculated vertically on ½ MS media in culture tubes containing different concentrations of IBA and NAA (0.1, 0.2, 0.3 mg/l). Thereafter, culture tubes were incubated at 27 ± 20C for 16 hours photoperiods under culture room up to 150 days. It was observed that at a higher concentration (0.3 mg/l) using both the hormones in- vitro roots and leaves were developed while at lower concentrations, response was comparatively poor. The average number of root and average root length per plantlet were recorded 4 and 8.2 cm respectively. Number of leaves were varied from 1- 6 with average 5.6 per plantlet while length of shoot/leaves ranged from 14.6 to 18.3 cm. Plants with well developed roots and leaves were placed in culture room for primary hardening under 27 ± 2 oC temperatures and 3000 lux light intensity for two months. Well survived plants then transferred to green house for secondary hardening under environment regime of 30 ± 2 0C temperature, 60-70 % relative humidity and 10000- 15000 lux light intensity. Secondary hardened plants transplanted in the field for further evaluation purpose to assess their performance under field conditions. The protocol developed needs up-scaling for improving efficiency of mass multiplication of date palm quality planting materials.