Influence of P-enriched compost application on economics and P use efficiency of a maize–wheat rotation system

Crop phosphorus(P) deficiency and poor utilization of added P is a major agricultural problem due to reduced solubility of soil P and rapid fixation or precipitation of applied P fertilizer in alkaline and calcareous soils. The effects of P-enriched compost and single superphosphate(SSP) fertilization on maize and wheat yields and P use efficiency in a maize–wheat rotation system were studied for three years. On a three-year average, grain yields of maize and wheat after application of P-enriched compost were increased by 18% and 24%, respectively, in comparison with sole addition of a recommended dose of SSP fertilizer. P-enriched compost addition to soil increased maize and wheat yields by 12% and 17%, respectively, compared to P fertilizer plus FYM incorporation. Soil available P concentration and P uptake were affected significantly by the addition of P-enriched compost. On average, increases in P recovery, use efficiency, and agronomic efficiency of 52%, 18%, and 43% were recorded in maize and increases of 50%, 23%, and 49% in wheat. P-enriched compost application yielded 30% and 32%higher economic returns in maize and wheat than SSP fertilization alone.

Strategies to enhance cottonseed oil contents and reshape fatty acid profile employing different breeding and genetic engineering approaches

Cottonseed oil is the valuable byproduct extracted after seed cotton processing for lint. It confers a huge contribution to total vegetable oil production and ranked the 2nd to meet global edible oil requirements. Over centuries, breeders mainly focused to improve lint production and fiber quality. Now attention has been given to improve the cottonseed oil percentage, its functional and nutritional properties. However, these efforts are less than other major oilseed crops which left cottonseed oil market behind in term of consumer demand and kept cott on seed oil industry at vuln erable positi on. Con siderable progress has been made to alter the relative percentage of fatty acid composition still intensified efforts have been required to meet the global oilseed demand. The objective of this review is to explore the cotton germplasm variation for seed oil carrying potential, its utilization in suitable breeding programs, seed oil biosynthetic pathways, major genes, and QTLs linked to quantity and quality enhancement of oil and deployment of modern genomic tools, viz., gene silencing and transgenic development to ameliorate its nutritional properties.

Quantifying Effects of Photoperiod, Temperature and Humidity on Flowering Initiation in Basmati Rice Lines

The results suggested that all the pure Basmati lines or genotypes initiate flowering within a specific range of day length duration and temperature. Delaying the transplanting date did not significantly affect the flowering time of studied Basmati lines. Maximum threshold of daily minimum temperature (MT) was 24°C during both the years. Likewise, maximum threshold of daily day-length (DL) durations was 12 hours and 18 minutes during both the study years. Results showed that the flowering was maximum when the MT and DL values were optimum as depicted by peak of the trend lines, where maximum lines flowered. Maximum flowering initiations took place when DL was about 11 hours and 15 minutes indicating Basmati as short day plant which flowers maximum when day lengths are shorter and dark or night duration is longer. During 2013, 1st date trial showed strong relationship between flowering initiation with dates of flowering during the flowering period as depicted by higher regression (R2 = 0.837) values. In 2nd date trial during the same year, the value is lower (R2 = 0.513) depicting less relationship of flowering initiation with the dates of flowering. The same trend was observed in 2014 trial. In 1st date trial, strong relationship between flowering initiation with dates of flowering during the flowering period as depicted by higher regression (R2 = 0.864) values, was observed. In 2nd date trial during the same year, the value is lower (R2 = 0.1789) depicting very poor relationship of flowering initiation with the dates of flowering, and the same trend (R2 = 0.0544) in 3rd date of trial.

Variation in Expression of <i>Sub</i>1 Gene and Association with Submergence Stress Related Traits in Advance Rice (<i>Oryza sativa</i>L.) Genotypes as a Tool of Climate Change Adaptation

Floods have now become most detrimental natural catastrophe worldwide due to radical climatic fluxes. Therefore, there is a dire necessity to develop a high yielding rice lines to deal with this scenario. For this purpose, a large scale experiment was conducted including one hundred and fifteen (115) rice genotypes having SUB1 gene imported from International Rice Research Institute (IRRI) Philippines, six local cultivars/approved varieties and three high yielding rice varieties i.e. Sabitri, IR6 and NSICRC222 being used as potential varieties in different countries of Asia as susceptible check and IR64-SUB1 as tolerant check. The genotypic screening was performed using two PCR-based DNA markers i.e. ART5 and SC3. Phenotypic screening was conducted in a natural pond to assess the interaction of SUB1 gene in natural stagnant flood water as well as the suitability of introgression of SUB1 gene into approved varieties and elite rice lines. The genotypes were assessed in terms of plant survival percentage, submergence tolerance index, physical condition, stem elongation, number of grains per panicle, thousand grain weight, grain yields and deviations in these traits after submergence stress. The PCR results suggested that both the primers ART5 and SC3 may be used as potential PCR-based markers for molecular screening of rice genotypes for SUB1 QTL. Furthermore, it confirmed the presence of SUB1 gene in all the lines imported from IRRI, while it was absent in all the local cultivars studied. All the genotypes with submergence tolerant gene (SUB1) showed significantly greater tolerance level in submergence stress of 14 days, as compared to other local cultivars/varieties, authenticating the effectiveness of SUB1QTL in conferring submergence tolerance. Significantly different performances of all the SUB1 genotypes in terms of all the studied traits indicate high Genotypic and Genotypic Environment Interaction (GEI) of SUB1QTL. Employment of SUB1 lines such as R105479:149-18, IR64-SUB1 and Rl05469:81-22-3 in breeding programs for developing flood tolerant rice varieties might further upsurge rice yields in flash flood areas. Correlation analysis revealed that plant survival percentage after submergence, reduced stem elongation during submergence and submergence tolerance index are very important traits for developing submergence tolerant lines.