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141.
David E. Page Morag Glen Desy Puspitasari Istiana Prihatini Abdul Gafur Caroline L. Mohammed 《Plant pathology》2020,69(4):685-697
Ganoderma philippii is a root pathogen of many woody plants in tropical regions and is particularly aggressive to Acacia mangium, which is grown on a 6-year rotation for pulpwood in Indonesia. The disease becomes progressively worse over each rotation and control measures have met with limited success. We studied the population genetics of G. philippii to evaluate the role of sexual and asexual reproduction in its mode of spread. Populations were genetically distinct with high levels of inbreeding, and clonal spread to adjacent trees increased after the first rotation. Despite the high levels of genetic diversity seen at all sampling scales, migration rates appear low. Measures to reduce the underground spread of the pathogen as well as methods to prevent the initiation of new infections from basidiospores will be needed to reduce the incidence of root rot in A. mangium plantations. 相似文献
142.
Timor M. EL-sherry Mohammed A. Abdel-Ghani Gamal B. Mahmoud Ahmed A. Ezzat 《Reproduction in domestic animals》2020,55(2):240-247
The aim of the present study was to investigate the effect of kisspeptin-10 (Kp10) injection on semen characteristics, testosterone (T) production and sperm rheotaxis using microfluidic devices in immature ram. Computer-assisted sperm analysis (CASA) with controlled flow velocity was used to explore the kinetic parameters of sperm and positive rheotaxis (PR %). PR % was defined as the number of PR sperms over the number of motile sperms. Healthy Ossimi rams were randomly divided into two groups; a saline-treated control group and Kp10-treated one (5 µg/kg body weight). Treatments were given by intramuscular injection once a week for 1 month. After 1 month, the semen was collected and evaluated weekly for 6 weeks, while the blood samples were collected every 2 weeks for the next 8 weeks. Semen properties were significantly affected by Kp10 injection (p < .01). The Kp10 increased the volume, sperm concentration and percentages of live sperm compared with those of control. Additionally, sperm trajectories and rheotaxis get improved by the injection of Kp10 with time. Furthermore, kisspeptin improved the secretion of testosterone levels throughout the period of study. In conclusion, injections of the Kp10 had a positive impact on semen characteristics as well as improved sperm rheotaxis of Ossimi rams in subtropics. 相似文献
143.
144.
Effects of phosphorous fertilizer on seedlings growth and nodulation capabilities of some popular agroforestry tree species of Bangladesh 总被引:1,自引:0,他引:1
Mohammad Belal Uddin Sharif Ahmed Mukul Mohammed Abu Sayed Arfin Khan Mohammed Kamal Hossain 《林业研究》2007,18(4):283-286
An experiment was conducted to assess the effect of Phosphorous (P) fertilizer (i.e. TSP or triple super phosphate @ 80 kg/hm^2) on seedling growth and nodulation capabilities of three potentially important agroforestry tree species (Acacia auriculiformis, Albizia lebbeck and Albizia procera) of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control (i.e. unfertilized soil). The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer. 相似文献
145.
Plantlets of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) had lower rates of net CO(2) uptake and higher rates of root respiration than greenhouse-grown seedlings. They also had a lower photosynthetic efficiency at high photosynthetic photon flux density, and exhibited significant depression of CO(2) uptake under water stress. The ability of plantlets to utilize high irradiance and to photosynthesize under conditions of water stress was enhanced by the presence of many roots. Carbon dioxide uptake rate increased with increasing root number, and decreased as the needle surface area/root surface area ratio decreased. High root number, low needle surface area/root surface area ratio, and elongated roots were associated with low apparent rates of shoot and root respiration. 相似文献
146.
Tolerance of bareroot and container-grown seedlings of black spruce (Picea mariana (Mill.) B.S.P.), jack pine (Pinus banksiana Lamb.), and eastern white pine (Pinus strobus L.) to competition from herbaceous vegetation was examined in the first five years after planting on a site in the Great Lakes/St. Lawrence forest of Ontario, Canada. Shoot and root morphological characteristics of various stocktypes were measured before planting and correlated with 5-year survival and growth following control and no control of herbaceous vegetation. For black spruce and jack pine, medium-sized bareroot stocktypes had greater relative 5-year stem volume growth in the presence of herbaceous vegetation than did container stock of either species or large bareroot stock of spruce. Relative volume growth was measured as the ratio of the cumulative stem volume increment in the presence of vegetation (Veg) to that in the absence of vegetation (NoVeg), i.e., the Veg:NoVeg ratio. In white pine, the Veg:NoVeg ratio of volume increment of medium container and large bareroot stocktypes exceeded that of small container and medium bareroot stocktypes. In jack pine, root collar diameter at planting and number of first-order lateral roots were positively correlated with 5-year Veg:NoVeg ratio of volume increment. In white pine, the Veg:NoVeg ratio was also positively correlated with root collar diameter at planting and with root volume. In black spruce, the ratio was not related to pre-plant morphology. Thus, for white pine and jack pine, certain pre-plant morphological features may be useful in forecasting the relative ability of different stocktypes to grow under herbaceous competition conditions in the field. 相似文献
147.
Rahman M. Motiur Yasushi Furukawa Isao Kawata Mohammed Mahabubur Rahman Mahbubul Alam 《Journal of Forest Research》2006,11(2):89-97
Empirical information regarding the role of homestead forests in household economy is essential in understanding the importance
of these resources. Identification of the factors that affect homestead forest production and understanding forest owners'
attitudes toward key forest management issues have great significance in making appropriate policy responses to manage these
resources on a sustainable basis. In Bangladesh, homestead forests are claimed to play an important economic role in rural
livelihoods, but no reliable quantitative information exists. This study was undertaken to investigate the role of homestead
forests in the household economy, examine if forest production and income vary across landholding size classes, to explore
the relationships of homestead forest production with species richness, education level, and household size, and to assess
the attitude of homestead forest owners toward key forest management issues. Results show that homestead forests contribute
15.9% of the household income and generate 51.4 man-days of employment per household per year. Production of homestead forests
significantly varies across landholding size classes. It was observed that forest production depends significantly on species
richness of homestead forests and the education level of forest owners. However, no such relationship was found between forest
production and household size. The study revealed that farming families depend more on forest income than nonfarming families.
Attitudes of forest owners toward key forest management issues differ significantly across landholding size classes. For example,
although the majority of the forest owners prefer fruit species to timber species, the percentage of respondents decreased
as the landholding size class increased, while the opposite trend was observed for timber species. The findings of this study
suggest that diversification of forests and extension of education amongst forest owners would improve forest production.
Furthermore, forest policy should address the concerns of the forest owners in different landholding classes and focus on
their specific requirements to enhance sustainable forest management. 相似文献
148.
Liposarcomas are rare neoplasms in domestic animals, but have been reported to occur in many species. In humans, liposarcoma is one of the most common malignant mesenchymal tumors. Classification of liposarcomas in humans has been well established and categorization by type can be of prognostic value; no such unique classification scheme has been established for liposarcomas in animals. Liposarcoma of the head and neck in humans are uncommon, and are rarely reported in the nasal cavity, sinuses, and nasopharynx. To our knowledge, a liposarcoma has never been reported in the nasal cavity of a domestic animal. In this report we describe a liposarcoma that developed in the nasal cavity of a cow, with local invasion into the oral cavity. 相似文献
149.
Shohat-Ophir G Kaun KR Azanchi R Mohammed H Heberlein U 《Science (New York, N.Y.)》2012,335(6074):1351-1355
The brain's reward systems reinforce behaviors required for species survival, including sex, food consumption, and social interaction. Drugs of abuse co-opt these neural pathways, which can lead to addiction. Here, we used Drosophila melanogaster to investigate the relationship between natural and drug rewards. In males, mating increased, whereas sexual deprivation reduced, neuropeptide F (NPF) levels. Activation or inhibition of the NPF system in turn reduced or enhanced ethanol preference. These results thus link sexual experience, NPF system activity, and ethanol consumption. Artificial activation of NPF neurons was in itself rewarding and precluded the ability of ethanol to act as a reward. We propose that activity of the NPF-NPF receptor axis represents the state of the fly reward system and modifies behavior accordingly. 相似文献
150.
Rahman MS Shohag AS Kamal MM Bari FY Shamsuddin M 《The Journal of reproduction and development》2012,58(2):219-222
The diameter of the preovulatory follicle (POF) and its effects on subsequent corpus luteum (CL) size and conception were studied in 38 lactating indigenous cycling buffaloes in the Mymensingh district of Bangladesh. Body condition score (BCS) at estrus was estimated for the buffaloes. The buffaloes were synchronized with two injections of a synthetic analogue of PGF2α administered 11 days apart. Transrectal ultrasonography was carried out at estrus and on days 5, 9, 12 and 16 post ovulation to determine the POF and successive CL size. Pregnancy was confirmed by ultrasound examination on day 40-45 post ovulation. Twenty one (55.3%) buffaloes were diagnosed as pregnant. The conception rates of thin (BCS ≤2.0), good (BCS 2.5-3.5) and fat (BCS glt;3.5) buffaloes were 7.7, 88.2 and 62.5% (χ2 = 19.54; P<0.05), respectively. The mean diameter of the POF at estrus was larger (P<0.01) in buffaloes that ultimately were diagnosed as pregnant compared with their nonpregnant counterparts (13.7 ± 0.3 vs. 11.2 ± 0.5 mm, respectively). The conception rates of buffaloes having small (9 to ≤ 12 mm), medium (>12 to ≤14 mm) and large (>14 to 16 mm) POFs at estrus were 9.1, 70.0 and 85.7% (χ2 = 13.87, P<0.01), respectively. On day 5 post ovulation, CL size was positively correlated (CL: r=.74, P<0.01) with POF diameter. Retrospective analysis revealed that on day 5 post ovulation, the pregnant buffaloes had higher (P<0.01) post ovulation CL sizes than their nonpregnant counterparts (15.6 vs. 11.8 mm). Similarly, on day 9 post ovulation, the difference in CL size (14.3 vs. 13.6 mm) between pregnant and nonpregnant buffaloes was significant (P<0.05). In conclusion, the diameter of the POF in buffaloes has a positive impact on the size of the post ovulation CL and conception. 相似文献