Cotton, a crop of choice, occupies the second premier position next to food crops in providing clothing. Though 53 species of Gossypium are available, only four species are cultivable and among the four, the major cultivable area falls under G. hirsutum. Though varieties with medium, superior medium, long and extra long staple cotton were released earlier, with the advent of machineries, ginning facilities, mills were literally requiring cotton fiber of any length. With the advent of Bt technology and the release of hybrids during 2002, cotton productivity had a momentum. However, considering the duration, cost involved in manual harvesting etc., farmers were looking for alternate option and High Density Planting System (HDPS) offered a promise in this direction. Farmers were looking for genotypes that could yield better under higher planting densities with fewer bolls per plant, synchronized maturity with uniform bursting. Efforts have been taken all over the World in this direction and India is not an exception. Handful of varieties fitting to this situation has been released from many of the Universities. This chapter essentially summarizes the genetic, agronomic, plant protection interventions and the futuristic requirements for achieving at least 700 kg of lint per hectare.
Part of the book: Plant Breeding
Non-coding RNA molecules are generally present in a dispersed manner throughout the genome. They may behave as long ncRNAs or convert into small RNAs of around 20–24 nts that are universally categorized using their size, function, or chromosomal position. ncRNAs are thought to play a vital role in regulating and modulating gene expression apart from their prospective role in several epigenetic mechanisms controlling specificity in biochemical pathways and phenotype development in clonal cells. They are also part of the natural defense system against viruses. ncRNA modulates genes by transcriptional and translational control of growth, development, and stress response alongside other RNA molecules. Some modes of action have unraveled in recent years. A lot more needs to be pondered upon for comprehending their involvement in the extremely intricate processes in a more wholesome manner. In this chapter, we will discuss the different ncRNA, their origin, classification, and their role in various physiological processes. Practical examples of the discovery of ncRNA in different crops and their functions have also been elucidated with the required details. The yield and quality enhancement, along with the better stress response being the aim of the crop improvement program, the prospective utilities of ncRNA are also explained in the subsequent part of the chapter.
Part of the book: Case Studies of Breeding Strategies in Major Plant Species