印度西孟加拉邦德赖地区梨竹生长基质标准化、萌发种子尺寸和实生苗生长

2008年2-4月,在印度西孟加拉邦德赖地区开展了试验,该试验对6个生长基质和3个种子的重量进行了分析,以找出其对梨竹萌发和实生苗生长的影响。与其他基质相比,将50 g的种子种在土壤、沙土和FYM以同一比例混合的基质中,种子萌发较好,实生苗生长更好。     

Isotope effect in superconducting fullerenes

The effect of isotopic substitution on the superconducting transition temperature, T(c), in alkali-doped C(60) has been examined. Paradoxically, it is found that a substantial decrease in T(c) with the increasing isotopic mass is possible even when the attractive interaction is not mediated by phonons but is instead of purely electronic origin. In particular, it is shown that the experimentally measured isotopic shifts are consistent with a recently proposed electronic mechanism. Further predictions are presented that can be tested by experiment.     

Enhancing milk and fertility performances using selection index developed for Indian Murrah buffaloes

Selection for genetically superior Murrah buffaloes under Network Project on Buffalo Improvement, India, is presently based on milk yield, and it was observed that even in the absence of any direct selection pressure applied on fertility, there has been a downward trend in fertility associated with the selection for milk yield. The aim of the study was to develop selection indices which include fertility besides milk yield in Murrah buffaloes. Data pertaining to 1,224 lactation records spread over a period of 19 years were recorded and analyzed in the study. The negative association of pregnancy rate (fertility) with a 305-day milk yield (?0.08?±?0.04) and wet average (?0.12?±?0.02) indicated the importance of incorporating fertility trait in the construction of selection index. Four types of selection indices were constructed and evaluated. Two indices were developed using expected producing ability 305-days milk yield (EPAMY) with 6.5 and 4 % fat in milk along with expected fertilizing ability (EFA). The other two indices developed consist of expected producing ability wet average (EPA WA) and EFA. The index involving (EPA WA and EFA) was found to be a more effective selection criterion in our herd, as the accuracy of index was more (0.61), in comparison to the index involving EPA MY and EFA. The robustness of selection index was assessed by increasing the relative economic values of included traits by 25 and 50 %, and accuracy of the index remains almost stable without much change. The developed selection strategy involving EPA WA and EFA should be considered for the genetic evaluation of Murrah buffaloes, as it has a potential for maximizing the lifetime reproduction and production performances of the breed.     

Electronic correlation effects and superconductivity in doped fullerenes

A theory of the electronic properties of doped fullerenes is proposed in which electronic correlation effects within single fullerene molecules play a central role, and qualitative predictions are made which, if verified, would support this hypothesis. Depending on the effective intrafulllerene electron-electron repulsion and the interfullerene hopping amplitudes (which should depend on the dopant species, among other things), the calculations indicate the possibilities of singlet superconductivity and ferromagnetism.     

Effect of an ectomycorrhizal fungus,Laccaria laccata,on Fusarium damping-off in Pinus banksiana seedlings

Damping-off caused by Fusarium oxysporum Schlecht in Pinus banksiana Lamb, was reduced significantly when inoculated with an ectomycorrhizal fungus, Laccaria laccata (Scop. ex Fr.) Berk. and Br. In paired culture, growth of F. oxysporum was significantly reduced by L. laccata. The number of colony forming units of F. oxysporum was reduced significantly in the rhizosphere of P. banksiana seedlings when inoculated with L. laccata. Spore germination and germ tube length of F. oxysporum was inhibited strongly by culture filtrate of L. laccata and root exudate of P. banksiana inoculated with L. laccata. Mycorrhizal seedlings had significantly higher amount of total soluble phenols than nonmycorrhizal ones.     

Studies in Forest Pathology Root Rot due to Rhizoctonia solani Kühn

A root rot disease of Phyllanthus emblica, Quercus serrata and Citrus sp. due to Rbizoctonia solani has been observed in the two tropical forests of Meghalaya in May to August. Seedling mortality was 39.4% in P. emblica, 38.6% in Q. serrata and 17.1% in Citrus sp. Older plants were resistant to this disease. High temperature and rainfall favour the disease development. The disease was observed in silt and clay soil with pH 6.10 and 6.38 and moisture content 22.8 and 24.6% respectively. The fungus grows over a broad temperature ranges (5 to 40°C) with optimum temperature at 20 to 35°C. The pathogenicity of the fungus was established. The fungus possesses quick and wide powers of saprophytic colonization of dead and healthy roots and soil. This is a new host record for this fungus on P. emblica and Q. serrata in India.