Genetic analysis of prolificacy in “Sikkim Primitive”—A prolific maize (Zea mays) landrace of North‐Eastern Himalaya

Prolificacy assumes significance for development of high‐yielding baby corn hybrids. “Sikkim Primitive” is a native landrace of North‐Eastern Himalaya, and is the highest prolific maize germplasm. So far, the genetics of prolificacy in “Sikkim Primitive” has not been deciphered. Here, a prolific inbred (MGU‐SP‐101) developed from “Sikkim Primitive” was crossed with four non‐prolific inbreds viz., LM13, BML7, HKI161 and HKI1128. Six generations (P₁, P₂, F₁, F₂, BC₁P₁ and BC₁P₂) of the crosses were evaluated at two locations during rainy season 2018. MGU‐SP‐101 possessed 2.50–3.78 ears per plant compared to 1.06–1.86 among non‐prolific inbreds. The variation for ears was the highest in F₂s (1–8), followed by BC₁P₁ (1–7) and BC₁P₂ (1–5). The quantitative inheritance pattern of prolificacy with prevalence of non‐allelic interactions of duplicate epistasis type has been observed. Dominance × dominance effect was predominant over additive × additive and additive × dominance effects. Total number of major gene blocks ranged from 0.41 to 2.86, thereby suggesting the involvement of at least one major gene/QTL governing the prolificacy. This is the first report of genetic dissection of prolificacy in “Sikkim Primitive”.     

Variation and inheritance of leaf angle, and its association with spot blotch (Bipolaris sorokiniana) severity in wheat (Triticum aestivum)

One thousand four hundred and seven spring wheat germplasm lines belonging to Indian and CIMMYT wheat programs were evaluated for their leaf angle and resistance to spot blotch caused by Bipolaris sorokiniana during three consecutive crop seasons, 1994–95, 1995–96 and 1996–97.Disease severity was recorded at six different growth stages beginning from tillering to late milk stage. Three crosses (M 3109 × Sonalika, HP 1808 × K 9006 and HD 2662 × K 9006) were made between genotypes with erect and drooping leaves. M 3109 was resistant, Sonalika susceptible while the other three lines possessed moderate resistance to spot blotch. Individually threshed F₂ plants were used to advance the generations. Leaf angle and spot blotch resistance were recorded in parents, F₁, F₃, F₄and F₅ generations. Leaf erectness in F₁ generation showed partial dominance. Evaluation of F₃, F₄ and F₅ progenies(120–150) revealed that leaf angle was under the control of few genes that appeared to be close to three. Germplasm lines with erect and semi-erect leaves displayed lower spot blotch severity than those having drooping and semi-drooping leaves. Lines homozygous for erect leaf posture in F₃,F₄ and F₅ generations showed significantly lower mean AUDPC than those with drooping leaves. A positive correlation (0.58) between leaf angle and AUDPC further indicated a positive influence of leaf erectness on severity to spot blotch disease. This revised version was published online in August 2006 with corrections to the Cover Date.     

First report of Fusarium solani causing wilt of Melia dubia

Melia dubia, a multipurpose tree species, is gaining importance to meet the demand supply gap of timber, plywood and pulpwood . In June 2016, a serious outbreak of wilt disease was observed in M. dubia seedlings planted in the Central Nursery of Forest Research Institute (FRI), Dehradun, India. The disease led to the destruction of one hundred thousand (100,000) seedlings. Earlier in June 2012, serious wilting of M. dubia seedlings was observed in Haryana, India. The pathogen was identified as Fusarium solani following standard laboratory procedures and sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA). The pathogenicity of three isolates has been proved under greenhouse conditions. This is the first report of F. solani causing wilt of M. dubia.     

Wheat somaclonal variants showing earliness, improved spot blotch resistance and higher yield

Somaclones (R₂, R₃ and R₄generations) were regenerated from immature embryos of two spring wheat varieties,HUW-206 and HUW-234. Many somaclones displayed improved earliness, enhanced resistance to spot blotch disease and increased yield over the parent. The superiority of variants for yield traits and disease resistance was established in R₄ generation, confirming the possibility of wheat improvement through somaclonal variation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nutrient-alginate encapsulation of in vitro nodal segments of pomegranate (Punica granatum L.) for germplasm distribution and exchange

The present paper demonstrates the potential of nutrient-alginate encapsulation of axenic nodal segments of pomegranate for synthetic seed technology, which could be useful in germplasm distribution and exchange. Nodal segments from in vitro shoot cultures derived from mature nodal explants (source A) or axenic cotyledonary nodes (source B) were encapsulated in calcium alginate hydrogel containing Murashige and Skoog's [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant 15, 473–497] medium (MS) supplemented with 4.44 μM benzyladenine (BA) and 0.54 μM naphthalene acetic acid (NAA). Of various concentrations of sodium alginate (1–6%) and the complexation solution of calcium chloride (50–125 mM), a combination of 3% sodium alginate and 100 mM calcium chloride was most suitable for formation of ideal synthetic seeds. Morphogenic response of encapsulated nodal segments to seven different planting media was evaluated. Encapsulated nodal segments of both the sources exhibited shoot development only in four selected media. Of the planting media evaluated, % sprouting (shoot development) was the highest in MS medium augmented with 4.44 μM BA and 0.54 μM NAA and lowest in (1/2) MSS medium. One step germination i.e. both shoot and root formation was possible only with encapsulated nodal segments of source B in MS, (1/2) MSS and natural soil + (1/2) MSS, with MS being most effective. Encapsulated nodal segments stored up to 30 days at 4 °C were capable of sprouting. Plants regenerated from the encapsulated nodal segments were hardened off and transferred to soil.     

Comparison of different laboratory methods with lysimetry for soil solution composition — experimental and model results

Compositions of soil solution obtained by the following methods were compared with those obtained by lysimetry: centrifugation; 2:1 extracts of air dried (2:1_dried) and field moist (2:1_moist) samples; saturation extracts; the ‘equilibrium soil pore solution’︁ method using columns with undisturbed (ESPS) and composited soil (ESPS_comp); and a method using pressure. Two soil depths of a Spodic Dystric Cambisol at Solling, Germany, were sampled with 10 to 12 replications. A coupled equilibrium model was used to describe the effect of soil to solution ratio on the solution composition. The model included multiple cation exchange and inorganic complexation, and for the subsoil solubility products of AlOHSO₄ and Al(OH)₃. Saturation extracts gave similar results as lysimetry and thus may be useful for calculating output fluxes. However, biological transformations (N mineralisation, solubilisation of organic matter) occurred during the preparation of saturation extracts. Composition of soil solutions obtained by either 2:1_dried extracts or centrifugation differed greatly from the results of other methods, indicating that these two methods may not be the best means to investigate equilibrium soil solutions. The values of molar ion ratios depended largely on the method used to obtain soil solutions: Ca²⁺/Al³⁺ ratios for each depth ranged from less than 0.3 (which suggests that liming is required urgently) to greater than 1 (liming not necessary). Modelling described the effect of soil to solution ratio on element concentrations for the methods pressure, saturation extracts, ESPS_comp and 2:1_moist extracts qualitatively with a few exceptions. The model suggested that differences in element concentrations using these methods may be mainly due to dilution, cation exchange and solubilisation of sparingly soluble salts, depending on the soil to solution ratio used.     

Efficiency of uterine fluid cytology in the diagnosis of subclinical endometritis in the water buffalo (Bubalus bubalis)

This study compared endometrial cytology vis‐a‐vis uterine fluid cytology for assessment of uterine health in clinically normal and subclinical endometritis (SE)‐affected buffaloes. Uterine fluid samples and endometrial samples were collected from the buffaloes (n = 38) at oestrus using blue sheath and cytobrush, respectively. The smears were stained with Field stain for 3 minutes, and a minimum of 400 cells were counted in each smear for determination of the percentage of polymorphonuclear (PMN) leucocyte. The incidence of subclinical endometritis, based on the cytobrush cytology, was 23.08%. The correlation between cytobrush cytology with uterine fluid cytology was positive and significant (r = .37; p = .02). The ratio of PMN leucocyte in cytobrush cytology to uterine fluid cytology was 1:2.4. ROC analysis revealed that the threshold value of 6.16% PMN leucocyte in uterine fluid cytology showed a diagnostic sensitivity and specificity of 100% in differentiating normal from SE‐affected buffaloes. In conclusion, collection of uterine fluid was easier compared to collection of endometrial samples using cytobrush and the percentage of PMN leucocyte in uterine fluid cytology can be used as a tool for diagnosis of subclinical endometritis in buffaloes.     

Blood gases and acid-base status of normal Zebu cattle

Nine adult bullocks were used for this study. The auricular artery was found to be convenient for collecting arterial blood samples. Samples were also taken from the jugular and auricular veins. The mean values of blood gas analyses from these animals are recorded.     

Blood gases and acid-base status of normal Zebu cattle

Nine adult bullocks were used for this study. The auricular artery was found to be convenient for collecting arterial blood samples. Samples were also taken from the jugular and auricular veins. The mean values of blood gas analyses from these animals are recorded.