Performance of poplar (populus deltoides bartr.) and its effect on wheat yield under agroforestry system in irrigated agro-ecosystem, India

The quantitative performance of wheat crop under 1-5 year old poplar plantations in irrigated agroecosystem was studied to ascertain the biological yield of tree and crop. Results revealed that growth and yield of wheat decreased significantly with the increase in poplar age. The per cent reduction in net grain yield was 17% under one year old poplar plantation, which increased to 52.15% under five year old plantation. The values of micro-meteorological parameters (light intensity and air temperature) were also low under plantations than in open condition and decreased with increase in plantation age. The current and mean annual increments in biomass and carbon storage curves exhibited a sharp increase of up to three years which thereafter increased with decreasing order. The carbon storage in the poplar biomass was estimated to be 34.075t/ha at the age of five years, which can be fixed as the maximum volume production rotation of this species under the prevailing conditions

Identification of QTLs for Drought-Related Traits in Alien Introgression Lines Derived from Crosses of Rice (Oryza sativa cv. IR64) × O. glaberrima under Lowland Moisture Stress

Drought is a major abiotic stress that limits rice productivity in rain-fed and upland ecosystems. African rice, Oryza glaberrima, has low yields but is tolerant to drought and other stresses. We evaluated 513 BC2F3 progenies from alien introgression lines (AILs) that were derived from crosses of Oryza sativa (IR64) × O. glaberrima. They were assessed for yield and other traits when grown under drought at two locations. Such conditions reduced grain production by 59% compared with the recurrent parent (IR64). However, 33 AILs had higher yields, thus demonstrating their potential as genetic material for transferring drought-related traits from O. glaberrima to O. sativa. A set of 200 AILs was selectively genotyped with 173 simple sequence repeat and sequenced tagged site markers. Molecular analysis showed that a mean of 4.5% of the O. glaberrima genome was introgressed in BC2F3 AILs. Our analysis revealed 33 quantitative trait loci (QTLs; including 10 novel) for different traits. O. glaberrima contributed 50% of the alleles to those newly identified QTLs, with one for grain yield per plant (ypp9.1) being new. A QTL at RM208 on chromosome 2 positively affected yield under stress, accounting for 22% of the genetic variation. Our identification of drought-related QTLs for yield and yield components will be useful to future research efforts in marker-assisted selectio