In Vitro Selection for Salt-Tolerant Strain of Poorbiraya, an Oil Crop

Abstract

Salinity is a major problem in Punjab. Its potential influence on plant productivity can be managed by biologically manipulating the plant, as plants vary widely in their sensitivity to high levels of salts. Among indigenous edible oils of Pakistan Brassica is second to cotton. It is grown mostly on rain-fed marginal lands. It is salt sensitive. In areas under saline conditions, most crops including oilseeds are generally being replaced by sugarcane. There is a dire need to change the cropping pattern towards the oil seed crops as at present production of cotton seed and other edible oil including rape/mustard, sunflower and safflower meet only 30% of the total requirement, of the country puts a burden of more than 50 million dollars per year. The main objective of present study was to develop salt tolerant strains of Poorbiraya by tissue culture techniques, which can be used to crop the salt affected soils. The findings of this project are likely to contribute to the ongoing efforts at the national level in the reclamation of vast agricultural lands being currently rendered as useless due to salinity. Moreover, this study is also likely to help in changing the cropping pattern towards oil seed crops, thereby contributing in increasing the oil seed production in the country. During the first year of studies in 1994, we were able to achieve: 1. Establishment of cultures form different vegetative parts of Poorbiraya plant. 2. Selection and propagation of embryogenic cell lines. 3. Salt-feeding trails on Poorbiraya cultures. 4. Selection and propagation of tolerant cell lines. In 2nd year study, 1995 we worked in: 1. Germination of Poorbiraya seeds on different salt combinations and evaluation of the seeding survival. 2. Study on cell growth in cultures from various parts of Poorbiraya plant. 3. Suspension cultures. 4. Poorbiraya shoot growth on saline media. 5. Plant regeneration in tolerant cell lines. 6. Improvements in methods of regeneration in saline conditions. 7. Plantlets formation. In 3rd and last year of the study to achieve targets of the project we on the basis of two years experience set our priorities and developed techniques on: 1. Formation of leaf embryogenic callus under saline conditions. 2. Regeneration of Poorbiraya plants by In vitro techniques. 3. Induction of salt-tolerance in regenerated plants; Survival rate of 80% was achieved under salt stress conditions. 4. Salt tolerant plants were shifted to Green House conditions; where they matured to reproduction and seed formation. The techniques developed as above would definitely prove way for not abanding a large area each year, as non-productive land in Punjab with the gradual build up of slat. The study will also help in decreasing the import bills of edible oils. This will also encourage local oil species which are otherwise materialized to indigenous climate and environmental conditions.