Exploring the link between more negative osmotic potential and ryegrass summer performance

This paper outlines recent research studying within-population variation in selected New Zealand perennial ryegrass cultivars, for traits related to tolerance of summer moisture deficit. Two clonal replicates of 220 genotypes from ‘Grasslands Nui’ (Nui, n=50), ‘Grasslands Samson’ Samson, n=80), and ‘Trojan’ (n=90) were exposed to a 1 month of moisture deficit challenge, with plant water relations measurements performed to evaluate putative drought-response mechanisms. Water use of individual genotypes ranged from 1000 g water/g DM indicating large within-population variation for this trait. Mean WUE for Nui, Samson, and Trojan was, respectively, 424±16, 412±10, and 319±9 g water/g DW (P<0.001), suggesting that commercial plant breeding may have indirectly reduced water use in modern cultivars without specific focus on water relations. Principal component analysis indicated more negative osmotic potential may contribute to reduced water use while maintaining yield under water deficit, giving a potential focus for future breeding selection targeting summer water deficit tolerance.fals

Crops that feed the world: Production and improvement of cassava for food, feed, and industrial uses

Cassava (Manihot esculenta Crantz) is one of the oldest root and tuber crops, used by humans to produce food, feed and beverages. Currently, cassava is produced in more than 100 countries and fulfils the daily caloric demands of millions of people living in tropical America, Africa, and Asia. Its impor-tance as a food security crop is high in Western, Central and Eastern Africa due to its ability to produce reasonable yields (\~10 t/ha) in poor soils and with minimal inputs. Traditionally a famine reserve and a subsistence crop, the status of cassava is now evolving fast as a cash crop and as raw material in the production of starch (and starch based products), energy (bio-ethanol) and livestock feed in the major producing countries. Cassava leaves, which are rich in protein and beta-carotenoids, are also used as a vegetable and forage (fresh or dehydrated meal) in various parts of the world. In recent years, some of the prob-lems in the production of cassava have been increasing infection with cassava mosaic disease (CMD), cassava brown streak dis-ease (CBSD) and cassava bacterial blight (CBB). Inherent post-harvest physiological disorder (PPD) and cyanogenic glycosides (CG) are some of the most prominent challenges for scientists, producers and consumers in the post-production systems. Collaborative research in participatory plant breeding is ongoing at leading international research institutes such as IITA and CIAT to improve crop resistance to virus diseases, reduce PPD and CG, and improve the overall nutritional characteristics. Further re-search should also focus on post-production systems by developing enhanced storage and transportation techniques, mechanisation (peeling, size reduction, drying and dewatering) and improved packaging. Moreover, a robust national policy, market development, and dissemination and extension program are required to realise the full potential of innovations and technologies in cassava production and processing