Fine Root Productivity and Turnover in Two Evergreen Central Himalayan Forests

Fine root production and mortality in central Himalayan evergreenforests consisting of Quercus leucotrichophora (banj oak) andPinus roxburghii (chir pine) were measured. Fine root productionand mortality decreased with increasing soil depth. Annual fineroot production was higher in the broadleafed forest than inthe coniferous forest, across months and seasons (1.3 and 1.5-timesmore living and dead root biomass, respectively in banj oakthan in chir pine). Live fine root production was 2508 kg ha^-1year^-1inchir pine forest and 3631 kg ha^-1year^-1in banj oak forest. Deadfine roots accumulated at a rate of 1197 and 1525 kg ha^-1year^-1inchir pine and in banj oak forest, respectively. In both forests,the greatest fine root production was recorded in the rainyseason followed by summer and winter seasons. Both soil androot nitrogen concentration decreased with increasing soil depth.Nitrogen uptake was higher in banj oak forest (12.1 kg ha^-1year^-1)than chir pine forest (7.2 kg ha^-1year^-1).Copyright 1999 Annalsof Botany Company Fine root production, fine roots, necromass, banj oak, chir pine, Quercus leucotrichophora , Pinus roxburghii .     

Genetics of transgressive segregation for yield and yield components in wheat

Three crosses of spring wheat (Triticum aestivum L. em Thell) involving six cultivars (WC29, WH291, SGP 14, RAJ. 1972, WH377 and HD 2329) were selected on the basis of combining ability analysis to study genetics of transgressive segregation for tillers/plant, grains/spike, 1000 grain weight and grain yield/plant using various mating designs. Diallel analysis indicated that both additive and non- additive components were significant for all the characters. On the basis of general combining ability and specific combining ability effects, the parents WH 291 and WH 377 were found to be good general combiners for tillers/ plant, 1000 grain weight and grain yield/plant. For grains/spike SGP 14 was found to be a good general combiner. The cross WH 377 × HD 2329 for tillers/plant, SGP 14 × Raj. 1972 for grains/spike and grain yield/plant and WC 29 × WH 291 for 1000 grain weight were found to be good cross combinations. Generation mean analysis indicated that the additive-dominance model was inadequate for all the characters in all the crosses except for 1000 grain weight in WC29 × WH291. Additive component was more pronounced than non-additive components for all the characters in all the crosses except for tillers/ plant in WH 377 × HD 2329. Predictions for transgressive segregants from F₃ was more accurate than that from generation mean analysis. However, prediction from both the sources were equally efficient if additive-dominance model was adequate. In general, observed frequencies of transgressive segregants were more in F₂ and BIPi than F₄ but the majority of them were discarded on progeny testing. Biparental mating had an impact in increasing the frequencies of transgressive segregants for different characters in all the crosses. The crosses, WH 377 × HD 2329 for grain yield/ plant, SGP 14 × Raj. 1972 for tillers/plant and WC 29 × WH 291 for grains/spike and 1000 grain weight were found to be potential crosses for transgressive segregants. A comparison of combining ability of parents and crosses, and observed and predicted frequencies of transgressive segregants indicated that the potential crosses for transgressive segregants were those that had high sea effects and involved high and low general combiners. The crosses involving low general combiners irrespective of their sea effects showed poor performance with respect to transgressive segregation.     

印度恒河蓝黑鲮与南亚黑鲮杂交个体的分子检测

利用鉴别性的同工酶位点从印度恒河水系的支流Banganga中检测到了蓝黑鲮(Labeo calbasu)与南亚黑鲮(Labeorohita)的一个杂交个体。线粒体DNA的单倍型模式进一步确认这个杂交个体的母本是河蓝黑鲮。     

Host specificity and seasonal distribution of Alloxysta pleuralis, a cynipoid hyperparasitoid of aphids in India

Abstract. 1. Alloxysta pleuralis (Cameron) is a cynipoid (Hymenoptera) hyperparasitoid of aphids (Homoptera) through their aphidiid (Hymenoptera) parasitoids.
2. It was recorded attacking five aphidiids, Lysiphlebus delhiensis (Subba Rao & Sharma), Trioxys indicus Subba Rao & Sharma, Aphidius uzbekistanicus Luzhetzki, Lipolexis scutellaris Mackauer and Lysiphlebia mirzai Shuja-Uddin (in order of preference) out of eight species of aphidiid parasitoids tested.
3. Percentage of hyperparasitism of aphids infesting cucurbits, cereals and pulses is higher than in solanaceous crops. Maximum hyperparasitism was recorded on the T. indicus/Aphis gossypii Glover/cucurbit complex.
4. The aphid host as well as the food plants significantly influence its efficiency.
5. A.pleuralis is abundant in northeastern Uttar Pradesh in winter (December–March) when large areas of pulses, cereals and cucurbits are infested with aphids serving as hosts for the primary parasitoids.     

Incidence and management of white grub, Schizonycha ruficollis on seedlings of teak （Tectona grandis Linn, f,）

In investigation was conducted annually from 2002 to 2005 between the second week of May and the end of September on the incidence of scarab beetle, Schizonycha ruficollis （Fabricius） in a teak （Tectona grandis L.f.） nursery at Ramdongari, Nagpur, India. The immature stages, that is white grubs of the scarab beetle damaged 14%-52% of teak seedlings in the nursery beds, whereas the adult of the species, that is scarab beetles, were recorded on three new host trees （ Ziziphus xylopyra, Acacia catechu and A. leucophloea） in addition to the reported hosts such as ziziphus （Z. jujuba and Z. mauritiana）. Beetles of the S. ruficollis started emerging from the nursery beds just after the pre-monsoon showers and continued for 10-18 days. While beetle of S. ruficollis defoliated tree hosts available in the surroundings, the immature stages of the beetle caused major damage by feeding on root systerfls of teak seedlings with symptoms of wilting and mortality in forest nursery beds. The result of chemical and biological treatments for the management of grubs of S. ruficollis in nursery beds indicated phorate 10% granular at the rate of 20 g/m^2 and chlorpyriphos 20% emulsifiable concentrate at the rate of 5.0 mL/m^2 to be effective. Grubs of S. ruficollis have not been recorded previously as a major pest of teak （T. grandis）. This is also the first report on occurrence of S. ruficollis adults on tree hosts such as Z. xylopyra, A. catechu and A. leucophloea. White grubs being pests of economic importance and the toughest insects to manage, information given in this paper on incidence, pest status and management of Schizonycha ruficollis is of importance to researchers and forest nursery managers.     

Biology of Bactrocera (Zeugodacus) tau (Walker) (Diptera: Tephritidae)

The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.     

On the possible occurrence of anisospory in some Hepaticae

PANT, D. D. & SINGH, R., 1989. On the possible occurrence of anisospory in some Hepaticae. Possible anisospory is reported for the first time in four species of Hepaticae, viz., Targionia indica Udar, Targionia hypophylla L., Cyathodium aureo-nitens Griff. (Mitt.), Cyathodium barodae Chavan. The report is based on observations of wide variations in size of spores comparable with those of anisosporous mosses of the family Orthotrichacae.