新几内亚凤仙组织培养和快繁技术研究

选取新几内亚凤仙具有顶芽或腋芽的茎段为外植体,诱导芽体萌发,进行繁殖培养。通过实验对比分别筛选出诱导芽分化和诱导生根的最佳培养基。实验结果表明：不同的激素水平对几内亚凤仙组培苗的生长有着显著的影响。其中最适宜的分化培养基为MS＋6-BA0.5 mg/L＋NAA0.1 mg/L;最适宜的生根培养基为1/2 MS＋IAA0.5 mg/L;最适宜的栽培基质为蛭石＋草炭＋珍珠岩（5∶3∶2）,成活率为95%。     

不同激素对碧云茶树丛生芽增殖培养的影响实验

为了获得碧云茶树的组培技术,加快其优良品种繁殖速度,2010～2011年进行了不同浓度的细胞分裂素6-BA和生长素NAA对碧云茶树丛生芽增殖培养的影响。结果表明,以MS为基本培养基,当6-BA为2.0 mg/L,NAA为0.2 mg/L时,对碧云茶树芽的诱导和增殖最有利,增殖率可达2.84;其中NAA差异不显著,6-BA差异显著。     

独蒜兰属植物研究现状

从地理分布、形态特征、生态学、繁殖栽培和资源开发等方面,对独蒜兰的研究进展进行了综述,为独蒜兰的进一步研究和开发利用提供了参考。     

改进培养方法提高组培快繁技术的初探

通过简化培养基成分，去除有机物、琼脂等，可降低试管苗成本；采用自然光替代日光灯，并结合黑暗培养，可减少设备投入．有利于工厂化育苗生产。     

Tissue-specific antioxidative and neurotoxic responses to diazinon in Oreochromis niloticus

The purpose of this study was to evaluate oxidative stress and neurotoxic potential of organophosphorus (OP) insecticide diazinon in the sentinel freshwater fish, Oreochromis niloticus. Antioxidant and acetylcholinesterase (AChE) enzyme activities and malondialdehyde (MDA) and protein levels were measured spectrophotometrically in gill, kidney, alimentary tract, and muscle tissues of fish treated with sub-lethal diazinon concentrations for 1, 7, 15, and 30 days. Dose-dependent inhibitions of AChE were observed in all the experimental fish. On the contrary of alimentary tract, MDA levels were elevated in kidney and muscle and gill was not affected. AChE and MDA levels intercorrelated in kidney and muscle tissues. Diazinon had increased superoxide dismutase (SOD) activities in all the tissues, while kidney was the most affected tissue. Tissue-specific alterations were observed on catalase (CAT) and glutathione peroxidase (GPx) activities; however, the activities were not changed in gill and muscle tissues for GPx and in gill, muscle, and kidney tissues for CAT. Protein levels decreased in kidney, muscle, and alimentary tract, while increased in gill and alimentary tract in 15 days. With respect to these results, diazinon has oxidative and neurotoxic potentials in O. niloticus. Observed changes with diazinon treatment were generally tissue-specific and dose-dependent.     

Unravelling the relationship between a seasonal environment and the dynamics of forage growth in grazed swards

It is well reported in the scientific literature that pastures can have similar net forage accumulation when managed with contrasting structures. However, we hypothesized that the dynamics of forage accumulation in grazed swards is linked to seasonal-environmental conditions. Marandu palisadegrass (Brachiaria brizantha [Hochst. ex A. Rich.] was used as the forage species model. The experimental treatments were four grazing heights (10, 20, 30 and 40 cm) allocated to experimental units according to a randomized complete block design with four replicates and evaluated throughout four contrasting environmental seasons (summer, autumn, winter–early spring and late spring). Under rainy and warm periods, greater net forage accumulation was observed in pastures maintained taller; on the contrary, during the mild and dry periods, net forage accumulation rate reduced as grazing height increased. Such patterns of responses were related to compensations between tiller population density and tissues flows during summer and late spring and the reduced capacity of taller canopies to compensate lower population with greater growth rates during autumn and winter–early spring. Grazed swards changed their patterns of forage growth as they transitioned from favourable to more abiotic stressful conditions, suggesting that seasonal adjustments in grazing intensities are necessary in order to maximize forage production.     

添加硅、硼元素对甘蔗组培苗生长的影响

以“新台糖１６号”甘蔗品种试管苗为材料,采用液体培养方法,以ＭＳ为基本培养基,附加激素ＢＡ ３ｍｇ／Ｌ、ＮＡＡ０．５ｍｇ／Ｌ,ＮａＳｉＯ３２００ｍｇ／Ｌ,苗增殖率比对照提高６８％,叶色浓绿、叶片挺直、硬、不早衰。比对照延长生长期２３ｄ。生根阶段,以ＭＳ为基本培养基,附加ＮＡＡ１ｍｇ／Ｌ、硼酸３０ｍｇ／Ｌ,生根数比对照增加５３％,根长、苗壮。     

洞庭湖区不同体色鲇不同组织同工酶的比较研究

采用聚丙烯酰胺垂直凝胶电泳技术(PAGE),对洞庭湖区两种体色(灰色、黄色)鲇的肝脏和肌肉组织中的苹果酸脱氢酶(MDH)、酯酶(EST)和乳酸脱氢酶(LDH)等3种同工酶进行研究。结果表明,在MDH同工酶中,两种鲇肝脏各有5条酶带,肌肉均有4条酶带表达;两种体色鲇鱼的同种组织中EST同工酶的酶谱不相同,黄色鲇鱼的EST同工酶检测出8条酶带,而灰色鲇鱼只有4条酶带;EST同工酶在不同组织中也表现出明显的组织特异性。在LDH同工酶中,黄色鲇肝脏有2条酶带,肌肉有1条酶带;而灰色鲇肝脏和肌肉中各有1条酶带。     

Population Studies of Limonium stocksii (Plumbaginacea) from a Salt Desert Near the Arabian Sea Coast

Abstract

A population of Limonium stocksii was studied for one year at the upper end of Manora Creek along the Arabian Sea coast, near Karachi, Pakistan. The community was divided into three zones. Soil pH varied from 8.1 to 8.5. Soil conductivity was highest (191 dS m^?1) in September and lowest (55 dS m^?1) in June. Soil water content was relatively low and varied from 1.6% in February to 9.5% in June. Limonium stocksii maintained a persistent seed bank, which peaked at 5,887 seeds m^?2 in May. Very slow growth was observed; however, plants in the intermediate zone showed better growth than the other two zones. Stem and leaf tissue water content were affected by salinity fluctuations, but root tissue water remained unaffected. Sodium (Na⁺) and chloride (Cl^?) accumulated in stems and leaves more than other ions. Leaves also accumulated a very high amount of magnesium (Mg⁺⁺) compared to roots and stems.     

Needle Collection Time for Nutrient Evaluation in Christmas Tree Production

Christmas tree needle sampling to evaluate nutrient need is an established practice. Data to support the recommended fall sampling time in Oregon and Washington were not found. In addition, the recommendation for needle sampling of Fraser fir in North Carolina was made without data from winter months. The goal for this article is to affirm or modify recommended needle sampling time. Needles of Douglas fir, Turkish fir, Nordmann fir, Noble fir, Grand fir, and Fraser fir Christmas trees were collected monthly for a year, dried, and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and boron (B). No single period was found for any species when needle nutrient concentration was stable for all elements determined. Needle collection time was chosen by integrating cultural practices, likelihood of nutrient deficiency, and needle nutrient concentration changes for species grown in an area. Needle collection is recommended during February in western Oregon and Washington. The current sampling time, fall, is logical for Fraser fir Christmas tree production in North Carolina.