Biotechnology scientists at the Anand Agriculture University in Gujarat have achieved a rare feat of propagating date palm through tissue culture, thus opening up bright prospects for the farmers in the Kutch region.
With Gujarat leading the second green revolution, tissue culture protocol in date palm cultivation will revolutionise agriculture in arid regions like Kutch, Anand Agriculture University Vice Chancellor A M Sheikh said.
Two scientists of the university Diwaker Patel and Subhash N, were recently given Dr Vikram Sarabhai Award for their outstanding contribution in the field of biotechnology for their work on date palm tissue culture.
The University's Plant Tissue Culture Laboratory is the first and the only laboratory in India which has successfully demonstrated micropropagation (mass multiplication through tissue culture) of Date Palm which is a very difficult crop for tissue culture, like other crops viz. oil palm and coconut.
“Scientists at AAU, Anand have lived up to the aspirations of farmers by successfully developing a tissue culture protocol for indigenous genotypes of Date palm. Tissue culture assures true-to-type multiplication of plants with known sex, production potential and quality leading to increased production and productivity, which in turn increases the income of the farmers”, Sheikh said.
Date palm, known as 'Kalpavriksh of Kutch', is an important fruit tree of arid and semi arid regions, due to its high tolerance to environmental stresses. It also has immense potential for generating good income in vast unproductive tracts of land.
The conventional methods of date palm propagation had many limitations. Seed propagation results into 50% of male tree, which are not productive for the farmers. The sex of the tree can only be known when the plant flowers, which is after six to eight years. Till this time, the farmers have to provide farm inputs on both male and female trees. However, for pollination and a good fruit, the farmer needs only about 2-3 male trees for every 100 females. The excess of male trees are not needed and hence are ultimately removed.
The other method of propagating date palm is through offshoots. This method is laborious and also has several limitations. Offshoots are produced in a limited numbers for a certain period in the lifetime of a young palm tree. The number of offshoots produced by an individual Date palm tree is highly variable and also varies from one cultivator to another.
Thus, the traditional methods of date palm propagation are a slow, laborious, time-consuming and expensive process in the long run.
Field evaluation of tissue culture raised plants of Date palm at Anand and Dantiwada have shown that the tissue culture raised plants have cent-per-cent field establishment (no mortality), early flowering, and profuse suckering. On flowering, all these plants were found true to type with vigorous growth.
DNA based molecular makers have also been employed to identify variant plants. However, no variation was observed among the tissue culture raised population, indicating the superiority of tissue culture protocol developed at AAU, and around 1500 plants are under hardening process in different stages, Subhash said.
According to farm journalist Mukul Bhatt, approximately 14 lakh highly heterogeneous trees are grown in Kutch region in about 12,493 hectares, which yield approximately 85,381 tonnes of fresh fruits every year. If the tissue culture revolution sets in, which carries an assurance of increase in quality and better productivity, the fruits from elite trees may start selling at Rs. 100 per kg.
The Gujarat government provided a fund of Rs. 50 lakh to undertake the ambitious project for technology development that involves removal of the offshoots from elite date palm trees of known performance through special tools by skilled workers (without injuring the mother plant). Offshoots of 5 to 10 kg are preferred for initiating the tissue culture work.
The outer coverings of the offshoot (leaf bases) are removed one-by-one and the shoot apex is taken out in a very skillful manner without any injury. Antibiotics, anti-fungal compounds (fungicides) and other chemicals are used to avoid any sort of contamination. The shoot apex is further resized and kept in glass vessels/containers which have pre-sterilised nutrient medium under aseptic conditions (free from microorganisms).
This material is then kept under controlled conditions of temperature (27°C) for a photoperiod of 16 hours and eight hours darkness (using fluorescent tubes). The inoculated material then establishes, proliferates on the media, and multiplies with every sub culture.
The stages involved in production of tissue culture plants of date palm are callus initiation followed by somatic embryo induction, development, maturation, germination and finally in vitro plantlet development. For further growth, the plantlets are then transferred to a green-house with controlled temperature and humidity conditions. These plants are then gradually acclimatised/ hardened by decreasing the humidity and increasing the temperature. These plants are later transferred to polythene bags containing soil based potting mixture for their further growth and development.
The plants with one compound leaf are fit to be transferred to the field for cultivation.
The scientists say that one offshoot can produce 2000 tissue cultured plants of date palm. DNA based tests conducted by NCL, Pune and AAU, Anand have clearly shown that all the plants produced through this protocol are genetically uniform (Clonal fidelity-test showed satisfactory results).
“Kutch contributes to around 90% of total date palm production in our country,'” Sheikh said. Drip irrigation is the best method to be adopted for it. Date palm requires a peculiar weather condition that is roots in water and crown in scorching heat (50 °C).