Plant Nanobionics and Its Applications for Developing Plants with Improved Photosynthetic Capacity

In the present scenario, the ever-growing human population, a decreasing availability of land resources and loss of agricultural productivity are the major global concerns, and these possess a challenge for scientific community. To feed the increasing world population, an increase in the crop productivity with available land resources is one of the essential needs. Crop productivity can be increased by engineering the crop plants for tolerance against various environmental stresses and improving the yield attributes, especially photosynthetic efficiency. Nanomaterials have been developed with new functional properties like improved solar energy harvest. With these nanomaterials, nanobionic plants were developed by the facilitated kinetic trapping of nanomaterials within photosynthetic organelle, that is, chloroplast. The trapping of nanomaterials/nanotubes improved chloroplast carbon capture, that is, photosynthesis by improving chloroplast solar energy harnessing and electron transport rate. Besides improving photosynthesis, nanotubes like poly(acrylic acid) nanoceria (PAA-NC) and single-walled nanotube-nanoceria (SWNT-NC) decrease the amount of reactive oxygen species (ROS) inside extracted chloroplast and influence the sensing process in plants, and these are beneficial for a number of physiological processes. The nanobionic approach to engineer plant functions would lead to an era of plant research at the interface of nanotechnology and plant biology. In this chapter, nanobionic approach, transfer of nanomaterial to plants and their offspring and its potential applications to improve photosynthesis will be discussed

Genetic Progress in 50 Years of Potato Breeding in India: Where Do We Stand?

Although the potato is a crop that was introduced in India, it has become a staple food and is grown in both the hills and plains. Potato breeding started in India in the 1950s’ and has contributed significantly to improving production. However, it is important to ascertain genetic progress in terms of changes in its yield over time. This study used the ‘Era trial’ methodology, wherein 22 potato varieties released in different decades ranging from 1968-2012 were evaluated in replicated multi-location trials for three consecutive years (2014-15, 2015-16 and 2016-17) in four potato growing zones of the country. The traits recorded were total tuber yield, marketable tuber yield and tuber dry matter content. Mixed model REML analysis showed significant differences among varieties and environments. Tuber dry matter content showed the least variation among varieties. The highest tuber yields were observed in the West-Central plains (WCP), while mean tuber yields were high in the North-Western plains (NWP). The zone-wise entry mean based broad-sense heritability estimates for all the three traits were high, although individual environment estimates observed low and moderate heritability too. Genetic gain results showed a positive trend for total and marketable tuber yields in NWP, WCP and Hill region (HR), while no gain was observed in the Eastern plains (EP) zone. The maximum annual rate of genetic gain for total tuber yield was 0.4%, 0.3% and 0.2% in WCP, HR and NWP. Positive genetic gain for tuber dry matter content was 0.2% in HR and 0.08% in WCP, while the other two zones had negative genetic gain for the trait. The annual rate of genetic gain for tuber yields and dry matter in potatoes does not commensurate with the future demand for the crop, underlining the need for holistic modern breeding techniques to boost genetic gains in potato breeding in India