Screening of Yardlong bean (Vigna unguiculata (L.) Walp.ssp. unguiculata cv.-gr. sesquipedalis) genotypes for seed,yield and disease resistance traits

Genetic Resources and Crop Evolution - Yardlong bean genotypes have wide variability in seed coat colours. This study sought to screen of yardlong bean genotypes based on seed coat colour,...     

Optimum plant stand and nutrient doses for summer groundnut under check basin irrigation and drip fertigation in light black soils of peninsular Western India

Abstract

A field experiment was conducted at Research Farm of ICAR-Directorate of Groundnut Research, Junagadh for consecutive three summer seasons of 2013, 2014, and 2015 with the objectives of identifying optimum plant density and nutrient doses under check basin irrigation and drip fertigation for higher productivity and net returns. The treatments were; three plant densities viz., 3,33,333 plants/ha (100% of recommended plant density; P1); 4,16,666 plants/ha (125% of recommended plant density; P2), and 4,99,999 plants/ha (150% of recommended plant density;P3) in main plots, and three nutrient doses viz., 18.75–37.5–22.5 NPK kg ha^?1 (75% of recommended nutrient dose; F1), 25-50-30 NPK kg ha^?1 (100% of recommended nutrient dose; F2), and 31.25–62.5–37.5 NPK kg ha^?1 (125% of recommended nutrient dose; F3) in sub-plots, and replicated thrice. The same sets of treatments were tested under both check basin irrigation and drip fertigation. The data were analyzed using split plot design. Pod yield, haulm yield, and net returns were significantly higher with P3 as compared to P1 under check basin irrigation but only haulm yield was found significantly higher with P3 under drip fertigation. Under check basin irrigation, NH₄–N, NO₃–N, and available P and K in soil were found in the order P1?>?P2?>?P3 (p?<?0.05) while in case of drip fertigation, differences were significant only for available K which was significantly higher in P1 over both P2 and P3. Under check basin irrigation, F2 i.e., application of 100 percent of recommended nutrient doses, being at par with F3, significantly improved pod yield, haulm yield and net returns over that with F1 however, differences were not significant under drip fertigation. NH₄–N, NO₃–N and available P and K in soil under both the irrigation systems were in the order F3?>?F2?>?F1 (p?<?0.05).     

Seed placement effects on seedling establishment in direct-drilled fields

Two techniques for measuring seed placement distribution, a seedling tracing method and a soil core X-ray technique, were compared. Based on these methods, three determinant parameters were developed to define seed distribution; variation of depth, variation of lateral width and depth variation between rows.In the presence of a desirable in-groove micro-environment, both seed depth variations within and between rows had a negative relationship with seedling emergence percentage. Correlations between emergence and lateral width were low. Variations in seed depth were found to be associated with the mechanisms of seed ejection, and with the depth control method used on the openers.At two trial sites (in a sandy and silt loam soil) a simple winged chisel opener gave higher plant emergence than an experimental chisel S/2000 opener, a slot opener, a modified slot opener and a triple disc opener.     

Variation between and within lentil landraces from Yemen Arab Republic

Summary The variation in 31 landraces of lentil collected from Yemen Arab Republic was partitioned to estimate the variation between populations and the variation between families within populations by studying a total of 568 progenies of randomly selected plants. There was significant variation between populations and between families within populations in seedling pigmentation, time to flower, time to maturity and plant height, but the predominant source of variation was between populations. This variation was unrelated to altitude of collection. The landraces were equally variable across characters. The implications of this analysis of variation on lentil breeding and germplasm collection are discussed.     

Quantitative HPLC analysis of withanolides in Withania somnifera

One of the most widely used herbs in Ayurvedic medicine is Ashwaghanda, Withania somnifera, a shrub commonly found on the Indian subcontinent. As this plant is increasingly becoming a popular adaptogenic in the western world, analytical methods for its identification and quality control are in demand. Thus, a HPLC method for the determination of withaferin A and withanolide D was developed. The system was successfully used to investigate the presence of the markers in different W. somnifera plant parts as well as to analyze their content in market products.     

Deterioration of rhizospheric soil health due to elevated ultraviolet-B

Enhancements in ultraviolet-B radiation (UV-B) due to stratospheric ozone depletion affect biological forms directly and indirectly. To investigate how belowground processes are affected under increased UV-B, a field experiment with mung bean cultivars (HUM-1 and HUM-12) was conducted. The responses of selected soil enzymes (β-glucosidase, cellobiohydrolase, polyphenol oxidase, glycine aminopeptidase, and phosphatase), microbial biomass C and N were assessed in rhizospheric and non-rhizospheric zones, along with measurements of phenol and flavanoid contents in roots and leaves. Test plants were exposed to two UV-B levels: (1) UVB, simulating 20% stratospheric O₃ depletion; and (2) UV0, the ambient UV-B. Elevated UV-B depressed shoot biomass by 24.8 and 15.9% and root biomass by 43.7 and 38.4% in cv. HUM-1 and HUM-12 compared with UV0. Although elevated UV-B caused an increase in phenol and flavonoid contents in leaves and roots, a reduction in the number of root nodules (32.4 and 24% in HUM-1 and HUM-2, respectively) and their fresh weight (27 and 23% in HUM-1 and HUM-2, respectively) was observed. Elevated UV-B caused microbial activity to shift from the rhizosphere to non-rhizosphere as indicated by increased microbial biomass N and soil enzyme activities in this zone.     

Transpiration Response of Maize Hybrids to Atmospheric Vapour Pressure Deficit

Maize (Zea mays L.) yield is often restricted by low soil water availability, particularly late in the growing season. To increase yields, genetic options for more effective use of available soil water are being explored. One option is to select genotypes that have restricted transpiration rate under high vapour pressure deficit (VPD) conditions so that soil water is conserved for use later in the growing season. While genetic variation for this trait has been identified within several crop species, such variation has never been explored in maize. The objective of this study was to examine transpiration rate of 35 single‐cross hybrids to determine whether hybrids can be identified that express limited transpiration under high VPD. Two sets of experiments were undertaken in which plants were exposed to a range of VPD in chambers. A two‐phase transpiration response was observed in 11 hybrids in which there was a threshold VPD above which transpiration rate was restricted. The VPD threshold varied from 1.7 to 2.5 kPa among these hybrids. Eight hybrids were included in both sets of experiments, and the same results were obtained in both experiments, indicating that expression of the trait was consistent.     

Gray wolf (Canis lupus) is a natural definitive host for Neospora caninum

The gray wolf (Canis lupus) was found to be a new natural definitive host for Neospora caninum. Neospora-like oocysts were found microscopically in the feces of three of 73 wolves from Minnesota examined at necropsy. N. caninum-specific DNA was amplified from the oocysts of all three wolves. Oocysts from one wolf were infective for the gamma interferon gene knock out (KO) mice. Viable N. caninum (designated NcWolfUS1) was isolated in cell cultures seeded with tissue homogenate from the infected mouse. Typical thick walled tissue cysts were found in outbred mice inoculated with the parasite from the KO mouse. Tissue stages in mice stained positively with N. caninum-specific polyclonal antibodies. Our observation suggests that wolves may be an important link in the sylvatic cycle of N. caninum.     

Metabolites of the fungistatic agent 2β-methoxyclovan-9α-ol by Macrophomina phaseolina

Biotransformation of 2β-methoxyclovan-9α-ol (1), a fungistatic agent against Botrytis cinerea, was investigated with Macrophomina phaseolina. Demethoxylation, regioselective oxidation at C-9 and C-13, and inversion of the configuration at C-9 of compound 1 afforded six oxidative metabolites, 2β-methoxyclovan-9-one (2), clovan-2β,9β-diol (3), clovan-2β,9α-diol (4), clovan-2β,13-diol-9-one (5), 2β-methoxyclovan-9α,13-diol (6), and clovan-2β,9β,13-triol (7). Compounds 5-7 are described here for the first time, and their structures were deduced by different spectroscopic techniques. The antifungal activity of new metabolites 5-7 was also evaluated against B. cinerea.