Landraces-potential treasure for sustainable wheat improvement

Genetic Resources and Crop Evolution - Agricultural production is facing serious threat from various biotic and abiotic stresses specifically under climatic challenges. It is becoming increasingly...     

Organogenesis and terpenoid synthesis in Mentha arvensis

Leaf discs obtained from field grown plants of Mentha arvensis were used to initiate multiple shoots on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (5 mg l(-1)) and naphthaleneacetic acid (0.5 mg l(-1)). Profuse rooting was achieved when the well-grown shoots were cultured on half strength MS medium supplemented with indole-3-acetic acid (2 mg l(-1)). The regenerated plantlets were hardened and successfully transferred to soil and grown to maturity. Tissues at different stages of differentiation were analyzed for their essential oil content and characteristic monoterpene pattern. Tissue culture raised plants show the same essential oil profile as that of the parent plant. However, tissues at early stages of growth show distinct changes in oil composition, such as high levels of pulegone in shoot cultures.     

Silica Gel from Rice Hull Ash: Preparation and Characterization

Rice hulls, a waste coproduct of the rice industry, is composed of 20% silica. The objectives of this study were to develop a method to recover silica from rice hull ash and produce silica gel, and to determine the physical and chemical properties of the rice hull silica gel (RHSG) relative to Trisyl 300, a commercial silica gel. Rice hull ash consisting of 61% silica and 36% carbon was dispersed in sodium hydroxide to dissolve the silica and produce a sodium silicate solution. The latter was titrated to pH 7 with 1M sulfuric acid to obtain a gel at neutral pH. The RHSG was aged, washed, and dried under specific conditions to get a final product that was slightly basic and had a moisture content >65%. Energy dispersive X-ray spectrometry indicated that silicon was the most abundant element present in RHSG and Trisyl 300. Elemental analyses by inductively coupled plasma emission spectroscopy indicated a greater concentration of sodium and sulfur in RHSG relative to that in Trisyl 300. RHSG surface area was 258 m²/g, which was slightly more than half that of Trisyl 300 particles; the particle pore diameter was 121 Å, which was more than twice that of Trisyl 300. Fourier transform infrared spectroscopy showed similarities in chemical structures for both the silica gel samples with respect to siloxane bonds, surface silanol groups, and adsorbed water. X-ray diffraction patterns for both the samples showed a broad peak between 15 and 35° 2θ diffraction angle indicating their amorphous nature. Scanning electron micrographs revealed that RHSG particles ranged in sizes from <5 to >40 μm, whereas Trisyl 300 particles were smaller, ranging in sizes from <5 to 25 μm and had a more uniform appearance. Silica gel production from rice hull ash alleviates the ricehull waste disposal problem and creates a commercially viable value-added product. RHSG has wide-ranging applications in a variety of industries, such as vegetable oil refining, pharmaceuticals, cosmetics, and paints.     

The evaluation of supply parameter,a new index of zinc availability in Mollisols

A new zinc supply parameter taking into account the intensity, quantity and buffering capacity and also the relative competitive influence of Cu²⁺, Fe²⁺, Mn²⁺ on the availability of Zn²⁺ has been tested. The proposed parameter correlated significantly and positively to Bray's per cent yield and zinc concentration in some parts of rice plant. The critical limit of soil zinc, in terms of this parameter at 15° and 30°C for rice, were 0.51 and 0.97 respectively. The required zinc addition to the deficient soil was also calculated on the basis of the values of this parameter at 30°C.     

Molecular expression and identification of caprine estrogen receptor gene 1 for fertility status in bucks

Estrogen and its receptors are essential for sexual development and reproduction. Oestrogen receptor alpha (ERα) is a nuclear receptor activated by the hormone oestrogen. In male, ERα is encoded by the gene ESR1 (oestrogen receptor1) responsible for better fertility. ESR1 is involved in the reabsorption of luminal fluid during the transit of spermatozoa from the testis to the head of the epididymis which is important for their survival and maturation during epididymal storage. The absence of ESR1 leads to reduced epididymal sperm content, reduced sperm motility and fertilizing ability. The present study was undertaken to investigate the expression and presence of ESR1 gene in fertile and low-fertile male goat breeds. We identified ESR1 gene through various molecular tools. Genotyping was carried out by high resonance melting analysis using Roche Light Cycler 480(LC-480) system and found three different genotypes. Genotypic frequency-AA (blue-0.67), BB(Red-0.2), AB(Green-0.08) with allele frequency A(0.71 and B (0.29). The predominance of this gene in head of epididymis in fertile bucks was confirmed by SDS-PAGE, Western blotting and immunohistochemistry. From the results, we corroborated that the present study provides a useful and effective way to predict male fertility in goat breeds, which in turn increases the percentage of fertility in flock leading to more number of offspring in a kidding season.     

Alternative tillage and crop residue management in wheat after rice in sandy loam soils of Indo-Gangetic plains

A 3-year field study was conducted to evaluate the effect of three tillage practices (conventional, zero and reduced/strip) with two nitrogen levels (120 and 150 kg N ha⁻¹) applied in primary strips and three crop residue management practices (removal, burning and incorporation) in secondary strips in wheat after rice. Reduced tillage resulted in significantly higher overall mean wheat yield (5.10 Mg ha⁻¹) compared to conventional (4.60 Mg ha⁻¹) and zero tillage (4.75 Mg ha⁻¹). Residue incorporation resulted in highest mean yield (5.86 Mg ha⁻¹) during third year. Maximum mean yield (6.1 Mg ha⁻¹) was obtained in reduced tillage followed by conventional tillage (5.8 Mg ha⁻¹) under residue incorporation in third year. The weed dry weight recorded at 30 days after sowing was highest (0.3 Mg ha⁻¹) under zero tillage and lowest under conventional tillage (0.16 Mg ha⁻¹). Among crop residue management practices, the highest dry weight of weeds (0.22 Mg ha⁻¹) was recorded under residue incorporation. The highest infiltration rate (1.50 cm h⁻¹) was recorded in residue incorporation followed by residue burning (1.44 cm h⁻¹) whereas; the lowest (0.75 cm h⁻¹) in zero tillage. Soil bulk density was the highest (1.69 Mg m⁻³) under zero tillage and the lowest in residue incorporation (1.59 Mg m⁻³). There were no changes in soil available P and K after each crop sequence in relation to tillage practices during first 2 years. Higher organic carbon (5.1–5.4 g kg⁻¹) was measured under zero tillage compared to other treatments. Residue incorporation increased soil organic carbon and available P while higher available K was monitored in burning treatment during the third year. These results suggest that reduced tillage and in situ incorporation of crop residues at 5 Mg ha⁻¹ along with 150 kg N ha⁻¹ were optimum to achieve higher yield of wheat after rice in sandy loam soils of Indo-Gangetic plains of India.     

Thyroid function in relation to reproductive efficiency in postpartum buffaloes (Bubalus bubalis) during summer and winter

Thyroid function was studied by estimating of plasma-protein-bound iodine (PBI), in buffaloes, from 0 to 57 days postpartum. PBI values (microgram/100 ml) were lowest on day 1 postpartum, followed by a gradual increase by day 57. The values were consistently lower (P less than 0.01) during summer (3.79 +/- 0.13 micrograms/100 ml), as compared to winter (5.06 +/- 0.27). A lower value (P less than 0.01) was obtained in animals requiring less than 30 days (3.53 +/- 0.45) or more than 30 days (4.88 +/- 0.27) for uterine involution. The values were 4.56 +/- 0.13, 5.03 +/- 0.68 and 2.72 +/- 0.50 in animals requiring less than 25, 25-50 and more than 50 days for initiation of follicular development (P less than 0.01). Similarly the values were 4.95 +/- 0.38, 3.95 +/- 0.45 and 4.03 +/- 0.59 in buffaloes having postpartum oestrus intervals less than 45, 45-90, and more than 90 days (P less than 0.01). Higher values (P less than 0.05) were obtained in conceiving (4.55 +/- 0.41), as compared to non-conceiving animals (4.21 +/- 0.31). It can be concluded that the thyroid function is depressed during summer and in poorly reproducing buffaloes.     

EST‐SSR analysis provides insights about genetic relatedness,population structure and gene flow in grass pea (Lathyrus sativus)

Grass pea (Lathyrus sativus) is an important food‐legume crop for resource‐poor farmers in the developing world. However, given its cultivation in the most underprivileged regions, the crop has not received appropriate scientific attention particularly from the genomic perspective, thereby giving it a status of genomic orphan. Nevertheless, some recent studies have attempted to develop modern molecular tools to strengthen the genetic and genomic research. In the present investigation, a comprehensive collection comprising 176 accessions was analysed using EST‐simple sequence repeats (SSRs). The SSR analysis revealed existence of a total of 51 alleles with an average polymorphic information content value of 0.35. A moderate level of gene diversity was noticed that ranged from 0.04 to 0.73 with an average of 0.43. Noticeably, two distinct subpopulations were recovered using cluster analysis. In addition, the presence of admixtures in population reflected the strong possibilities of gene flow between the accessions across the geographical boundary. In summary, we provide additional insights about the informativeness of available EST‐SSR markers along with an extended understanding of relatedness, genetic structure and gene flow in an under‐researched legume crop.