Benefit-cost analysis of raising Pinus wallichiana seedlings in different capacities/sizes of root trainers in the nursery

Modern nursery methods of seedling production in different sized root trainers,were compared by raising seedlings of Pinus wallichiana involving costs incurred and benefits received. In order to provide a common basis for the comparisons,the study involved the raising of 1000 seedlings annually on a continuous basis for seven years. A relative economic analysis of raising P. wallichiana seedlings in 300,150 and 100 cm3 root trainers was carried out and we estimated that the root trainers of 300 cm3 capacity...     

银鲳形态特征与DNA条形码研究

鲳属鱼类广泛分布于中国沿海,为重要经济鱼种,鲳属鱼类因外部形态存在较大的相似性,分类一直存在分歧。本研究于2010年10月—2012年9月采集科威特(科威特北部海域)、巴基斯坦(松米亚尼湾、奥尔马拉和伯斯尼)、北部湾和台湾近海的银鲳样品,对其形态特征进行重新描述,并对其DNA条形码开展了研究。银鲳的主要形态特征为背鳍Ⅶ-Ⅷ-39～43;胸鳍21～29;臀鳍Ⅴ-Ⅵ-35～41;尾鳍26～28。鳃耙细弱、稀疏,2～3 8～9=10～12。头部后上方侧线管的横枕管丛和背分支丛后缘呈浅弧形,腹分支丛较背分支丛略长,向后延伸未达背鳍起点,呈峨眉状。脊椎骨数37～38。结合GenBank中所有拉丁学名为Pampus argenteus的COⅠ基因进行同源序列比较发现,所有个体单倍型明显分为4个组群,而从氨基酸遗传差异和组群间遗传距离可以看出,4个组群应为不同的有效种;GenBank中只有FJ384702与本研究序列结果相近。本研究描述了银鲳形态特征,并给出其正确的COⅠ基因DNA条形码序列,为深入开展鲳属鱼类的分类研究奠定了基础。     

Range extension of four highland agamid lizards in Shimshal Pamir, Pakistan

As part of the Sino-Pak trans-boundary cooperation for conservation and sustainable development in Pamir border region,World Wild Fund (WWF)-Pakistan conducted a preliminary social,economic and ecological survey in the Shimshal-Pamir Lakes area in July 2009.The purpose of the study was to explore potentials and opportunities for future collaborative conservation of some species,habitats and high altitude ecosystems in the border region between China and Pakistan.The two-week herpetological study in the Shimshal Pamir area of Khunjerab National Park (KNP) along Pakistan-China border was an integral part of the survey,conducted exclu-sively to document reptilian fauna with a special emphasis on investigating their occurrence,distribution and status in the study area.Field investigations were performed during daytime when it was hot enough and reptiles were active,basking or feeding.A total of 15 specimens belonging to four species of the Agamidae family were captured by striking stones and beating bushes with sticks.Collected specimens were preserved using 10% formalin solution,tagged with field information and stored in Zoological Survey Department,Karachi for future reference.Laboratory investigations were carried out for pholidosic counts and morphometric measurements.A detailed review of relevant literature,habitat characteristics and laboratory investigations revealed the occurrence of Laudakia himalayana,L.pakistanica,L.tuberculata and L.badakhshana at 4,082 m,4,172 m,4,005 m and 4,240 m asl,respectively,which are much higher altitudes as compared to the previously reported heights of 3,353 m,3,200 m,2,500 m and 2,400 m asl.The terrain offers a variety of ecological barriers,in the form of fast and freezing running waters and massive glaciers with peculiar harsh climatic conditions prevailing for nine months of the year,which restricts species migration and thus increases endemism.Although one of the four species recorded from the study area,i.e.L.pakistanica is endemic to Pakistan,L.tuberculata and L.badakhshana are new records from Shimshal,Pakistan,so a detailed investigation is suggested for further herpetological records from the study area.     

Estimation of economic threshold level of alligator weed (Alternanthera philoxeroides (Mart.) Griseb.) to Tackle Grain quality and yield Losses in Rice

Alligator weed (Alternanthera philoxeroides) is the most troublesome invasive weed in transplanted rice ecosystems worldwide. A two-year field study was conducted to estimate economic threshold levels and the season long competitive effect of six alligator weed densities (0, 2, 4, 8, 16, and 32 plants m^?2) on yield and quality traits of transplanted rice. A gradual linear incline in dry weight of alligator weed was observed with an increase in its density from 2 to 32 plants m^?2. Maximum N (15.93–18.26 kg ha^?1), P (15.10–16.46 kg ha^?1) and K (16.34–17.81 kg ha^?1) uptake by alligator weed was recorded at its density of 32 plants m^?2. More micronutrient loss to the tune of 6.53, 47.92, 19.99, and 38.42 mg kg^?1 for Cu, Fe, Zn, and Mn, respectively was observed at the same density. Increasing density of alligator weed caused more losses in paddy yield (up to 21.37–23.78%), amylose and rice grain protein contents. According to a nonlinear hyperbolic regression model, maximum paddy yield loss of rice at asymptotic value of alligator weed density was 38.8% during 2011 and 42.4% during 2012. Economic threshold value of alligator weed was estimated 1.5 and 1.3 plants per m² during 2011 and 2012, respectively.     

Evaluation and management of acetyl-CoA carboxylase inhibitor resistant littleseed canarygrass (Phalaris minor) in Pakistan

A field survey was conducted for the sampling of Acetyl-CoA carboxylase (ACCase) inhibitor resistance littleseed canarygrass, a major weed of wheat, from Punjab, Pakistan in 2014 for confirmation of resistance. The surveyed regions encompassed four different cropping systems including rice–wheat, maize–wheat, cotton–wheat and mixed cropping. Dose–response assay was conducted for confirmation of resistance. Efficacy of herbicide mixtures including clodinafop–propargyl, metribuzin, pinoxaden and sulfosulfuron at a range of doses was investigated to manage littleseed canarygrass. Results revealed that all populations were resistant to fenoxaprop except PM-BWL-2. The higher level resistance (6.5) was found in populations collected from rice–wheat cropping system. The tested herbicide mixtures at 75% and 100% of the recommended dose of each mixture component provided the effective control of resistant littleseed canarygrass. Mixtures at 50% provided more than 80% control and reduced growth and seed production potential of surviving plants. The confirmation of ACCase inhibitor resistance as the first case of herbicide resistance in Pakistan, leads us to discourage use of ACCase inhibitor herbicides alone. However, herbicide mixtures at 75% and 100% of the recommended dose are suggested to manage this weed for sustainable wheat production in the surveyed cropping systems.     

Reconsidering betaine as a natural anti-heat stress agent in poultry industry: a review

Betaine is found ubiquitously in plants, animals, microorganisms, and rich dietary sources including seafood, spinach, and wheat bran. The chief physiological role of betaine is to function as a methyl donor and an osmolyte. Betaine also acts as an osmolyte, to maintain the avian’s cellular water and ion balance to improve the avian’s capacity against heat stress via preventing dehydration and osmotic inactivation. It helps in maintaining the protective osmolytic activity, especially in heat-stressed birds. Betaine may promote various intestinal microbes against osmotic variations and thus improve microbial fermentation activity. Previous studies showed that dietary supplementation of betaine in poultry diets could positively affect nutrients’ digestibility, reduce abdominal fat weight, and increase breast meat yield. In addition, betaine has been reported to protect internal organs and boost their performance. Its inclusion in poultry diet is sparing essential amino acids like choline and methionine. In addition, it may play an important role in lean meat production by positively affecting the lipid metabolism with increased fatty acids catabolism and thus reducing carcass fat deposition. The aim of this review article was to broaden the knowledge regarding betaine and its importance in the poultry industry to cope with the heat stress problem. Moreover, it should be added to the diet as a natural anti-stressor through different routes (water/feed) to overcome the heat stress problem. However, further studies need to be conducted at the genetic and molecular basis to elucidate the mechanism behind the betaine as a natural anti-heat agent to decrease the heat stress problem in the poultry industry.     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

大豆根部水压胁迫耐逆指数遗传体系解析

大豆是重要的植物蛋白质和植物油脂来源,干旱是影响大豆产量的重要环境因子之一。为解析大豆耐旱性的遗传基础,本研究在PEG水压胁迫条件下,对由409个家系组成的巢式关联作图群体(具有1个共同亲本的2个重组自交系群体组成)进行叶片脯氨酸含量测定,通过限制性二阶段多位点全基因组关联分析(restrictivetwo-stagemultilocus genome-wide association study,RTM-GWAS),解析了大豆根部水压胁迫耐逆指数(root hydraulic stress tolerance index,RHSTI)的遗传体系。结果表明,在春季和夏季环境下,3个亲本蒙8260(共同亲本)、通山薄皮黄豆甲和正阳白毛平顶在RHSTI上均存在显著差异,其衍生群体RHSTI表型变异丰富,变幅分别为0.11~2.94和0.03~1.93,遗传力分别为97.7%和97.9%;2个环境联合分析发现,家系遗传力和家系与环境互作遗传力分别为37.9%和60.1%,说明群体RHSTI的变异受遗传和环境共同控制。通过RTM-GWAS方法,共检测到45个与RHSTI相关的QTL,分布在大豆18条染色体上,可以解释37.58%的表型变异,其中7个QTL的表型贡献率超过1%,为大贡献位点;这些QTL中,有34个位点与环境存在显著互作,可以解释12.50%的表型变异。结合PEG胁迫下大豆转录组数据,在定位区间500kb范围内共筛选到38个差异表达基因,可归为ABA响应因子、逆境响应因子、转录因子、发育因子、蛋白代谢因子、未知功能和其他等7类,其中逆境响应因子、转录因子和发育因子是最大的3类;其中位于主效位点的6个基因,与ABA响应因子、逆境响应因子、转录因子相关,应为主要候选基因。上述结果表明,大豆耐旱性是一个由多位点、多基因控制的复杂数量性状,且与环境存在互作,遗传基础复杂。研究结果为大豆耐旱性分子育种提供了依据。