In planta transformation of pigeon pea: a method to overcome recalcitrancy of the crop to regeneration in vitro

Development of transgenics in pigeon pea remains dogged by poor plant regeneration in vitro from transformed tissues and low frequency transformation protocols. This article presents a non-tissue culture-based method of generating transgenic pigeon pea (Cajanus cajan (L.) Millisp.) plants using Agrobacterium-Ti plasmid-mediated transformation system. The protocol involves raising of whole plant transformants (T0 plants) directly from Agrobacterium-infected young seedlings. The plumular and intercotyledonary meristems of the seedling axes are targeted for transformation. The transformation conditions optimized were, pricking of the apical and intercotyledonary region of the seedling axes of two-day old germinating seedlings with a sewing needle, infection with Agrobacterium (LBA4404/pKIWI105 carrying uid A and npt II genes) in Winans' AB medium that was added with wounded tobacco leaf extract, co-cultivation in the same medium for 1h and transfer of seedlings to soilrite for further growth and hardening and subsequent transfer of seedlings to soil in pots in the greenhouse. Out of the 22-25 primary transformants that survived infection-hardening treatments from each of the three experiments, 15 plants on the average established on the soil under greenhouse conditions, showed slow growth initially, nevertheless grew as normal plants, and flowered and set seed eventually. Of the several seeds harvested from all the T0 plants, six hundred were sown to obtain progeny (T1) plants and 350 of these were randomly analysed to determine their transgenic nature. PCR was performed for both gus (uid A) and npt II genes. Forty eight of the 350 T1 plants amplified both transgenes. Southern blot analysis substantiated the integration and transmission of these genes. The protocol ensured generation of pigeon pea transgenic plants with considerable ease in a short time and is applicable across different genotypes/cultivars of the crop and offers immense potential as a supplemental or an alternative protocol for generating transgenic plants of difficult-to-regenerate pigeon pea. Further, the protocol offers the option of doing away with a selection step in the procedure and so facilitates transformation, which is free of marker genes

An introduction to global production trends and uses, history and evolution, and genetic and biotechnological improvements in cotton

Cotton plant has been domesticated in tropical and sub‐tropical climates of the world but severe climate is not suitable for good lint yields. Globally, cotton is grown on an area of more than 30 million hectare and possesses a global production of more than 70 million tons of seed cotton. The average yield of seed cotton in the world is more than 2000 kg/ha and the largest cotton producer in the world (China) is getting an average yield that is double to the world average. China, India, the United States, and Pakistan are the largest seed cotton producers in the world. Cotton crop possesses an inevitable role in the global industries, economy, and culture. In this chapter, the history and evolution of the cotton, the global production trends of cotton, uses, and the role of biotechnology in improving cotton production have been discussed