Amino Acid Composition of the Protein from a Mushroom (Pleurotus sp.)

Approximate analyses of mushroom protein (Pleurotus sp.) revealed that it contains 2.78% protein and 0.14% nonprotein nitrogen on a fresh-weight basis. A total of 17 amino acids, including all the essential amino acids, were qualitatively identified. Quantitative estimation of essential amino acids showed that, except for methionine and phenylalanine, all are in fairly high concentration. From these studies, it was concluded that the supplementation of this mushroom with cereal diet would help to overcome lysine deficiency.     

Nutrition Requirements of Pleurotus flabellatus

The mycelium of Pleurotus flabellatus was grown in a synthetic medium to obtain accurate information on its nutritional requirements. Among various carbon sources tried, the organism was found to utilize hexose sugars more readily than other sugars. Ammonium citrate was found to be the best source of nitrogen. The yield of dry matter increased as the concentration of nitrogen was increased up to a certain stage beyond which there was no increase in the yield, but the crude protein content of the mycelium increased. Detailed studies on the effect of varying the concentrations of other major nutrients, i.e., potassium, phosphorus, calcium, and magnesium, on the growth and crude protein content of the mycelium were also carried out. Optimal pH range was fairly broad, lying between 4.5 to 7.5.     

Description of Paktylenchus tuberosus gen. n., sp. n. (Nematoda: Tylenchinae)

Paktylenchus tuberosus gen.n., sp.n. is described and illustrated from soil around Solanum tuberosum from Kaghan Valley, Pakistan. Paktylenchus gen.n, can be distinguished from the most closely related genus, Agelenchus Andrassy, 1954, by the distinct longitudinal striae, three incisures in the lateral field, and absence of males. Paktylenchus tuberosus shows affinities to Coslenchus Siddiqi, 1978 but differs in having an oblique vagina-to-body axis and a prominent sunken vulva with vulval flaps. Four genera of the subfamily Tylenchinae are also discussed herein.     

Preparation and properties of L-asparaginase from green chillies (Capsicum annum L.)

Green chillies(Capsicum annum L.) and tamarind (Tamarindus indica) contain appreciable amount of L-asparaginase. The enzyme was purified 400-fold from green chillies, by successive precipitations with ammonium sulphate and sodium sulphate, Sephadex-gel filtration and affinity chromatography and the purified enzyme was homogenous on gel electrophoresis. The enzyme exists in two forms, only one having antitumour activity. The purified enzyme has a molecular weight of 120,000 ±500. The N-terminal and the C-terminal amino acids are alanine and phenylalanine, respectively. The enzyme has a sharp optimum pH of 8.5 and a temperature optimum of 37‡C. It is stable upto 40‡C. The energy of activation is 3 kilo calories. The K_m value for the enzyme is 3.3. mm. The enzyme has little action on D-asparagine, which is a strong inhibitor. The enzyme has inseparable glutaminase ctivity and is thus an asparaginase—glutaminase. In addition, it possesses urease activity.     

Salinity Stress in Wheat: Effects,Mechanisms and Management Strategies

Salinity stress is a major threat to global food production and its intensity is continuously increasing because of anthropogenic activities. Wheat is a staple food and a source of carbohydrates and calories for the majority of people across the globe. However, wheat productivity is adversely affected by salt stress, which is associated with a reduction in germination, growth, altered reproductive behavior and enzymatic activity, disrupted photosynthesis, hormonal imbalance, oxidative stress, and yield reductions. Thus, a better understanding of wheat (plant) behavior to salinity stress has essential implications to devise counter and alleviation measures to cope with salt stress. Different approaches including the selection of suitable cultivars, conventional breeding, and molecular techniques can be used for facing salt stress tolerance. However, these techniques are tedious, costly, and labor-intensive. Management practices are still helpful to improve the wheat performance under salinity stress. Use of arbuscular mycorrhizal fungi, plant growth-promoting rhizobacteria, and exogenous application of phytohormones, seed priming, and nutrient management are important tools to improve wheat performance under salinity stress. In this paper, we discussed the effect of salinity stress on the wheat crop, possible mechanisms to deal with salinity stress, and management options to improve wheat performance under salinity conditions.     

Exploration of Genetic Pattern of Phenological Traits in Wheat (<i>Triticum aestivum</i> L.) under Drought Stress

Drought is the major detrimental environmental factor for wheat (Triticum aestivum L.) production. The exploration of genetic patterns underlying drought tolerance is of great significance. Here we report the gene actions controlling the phenological traits using the line × tester model studying 27 crosses and 12 parents under normal irrigation and drought conditions. The results interpreted via multiple analysis (mean performance, correlations, principal component, genetic analysis, heterotic and heterobeltiotic potential) disclosed highly significant differences among germplasm. The phenological waxiness traits (glume, boom, and sheath) were strongly interlinked. Flag leaf area exhibits a positive association with peduncle and spike length under drought. The growing degree days (heat-units) greatly influence spikelets and grains per spike, however, the grain yield/plant was significantly reduced (17.44 g to 13.25 g) under drought. The principal components based on eigenvalue indicated significant PCs (first-seven) accounted for 79.9% and 73.9% of total variability under normal irrigation and drought, respectively. The investigated yield traits showed complex genetic behaviour. The genetic advance confronted a moderate to high heritability for spikelets/spike and grain yield/plant. The traits conditioned by dominant genetic effects in normal irrigation were inversely controlled by additive genetic effects under drought and vice versa. The magnitude of dominance effects for phenological and yield traits, i.e., leaf twist, auricle hairiness, grain yield/plant, spikelets, and grains/spike suggests that selection by the pedigree method is appropriate for improving these traits under normal irrigation conditions and could serve as an indirect selection index for improving yield-oriented traits in wheat populations for drought tolerance. However, the phenotypic selection could be more than effective for traits conditioned by additive genetic effects under drought. We suggest five significant cross combinations based on heterotic and heterobeltiotic potential of wheat genotypes for improved yield and enhanced biological production of wheat in advanced generations under drought.     

Enhanced shoot organogenesis in Cassia angustifolia Vahl. — a difficult-to-root drought resistant medicinal shrub

In vitro regeneration was achieved through callus culture derived from cotyledon explants of Cassia angustifolia Vahl. on MS (Murashige and Skoog, 1962) medium. Calli were induced from cotyledon explants excised from aseptic 14?days old seedlings on MS medium containing 2,4-D (2,4-dichlorophenoxy acetic acid) and 2,4,5-T (2,4,5-trichlorophenoxy acetic acid) at different concentrations with 3% sucrose and 0.8% agar. Optimal growth of callus was obtained at 5.0???M 2,4-D, which was proved to be the best for shoot regeneration when sub cultured onto MS medium supplemented with cytokinins either alone or in combination with an auxin. Maximum number of shoots (23.2?±?1.4) were produced at 5.0???M 6-benzylaminopurine (BA) and 0.4???M ??-naphthalene acetic acid (NAA). Regenerated shoots produced prominent roots when transferred to half strength MS medium supplemented with 1.0???M indole-3-butyric acid (IBA) and 5.0???M phloroglucinol (PG). Rooted plantlets thus developed were hardened and successfully established in the soil. This protocol yielded an average of 23 plants per cotyledon explant over a period of 4?months.     

A GRAS-Type Transcription Factor with a Specific Function in Mycorrhizal Signaling

Download : Download video (88MB)