接种固氮菌对桉树苗木土壤酶的影响

本实验在桉树组培瓶苗移栽时,用浸根接种方法为桉树苗接种培养好的自生固氮菌。试验在标准苗床中进行,采用随机区组设计。设置4个处理(3个菌种处理和1个不接种对照处理),处理间设有保护行。观察接种固氮菌分别对桉树苗木土壤蛋白酶、土壤多酚氧化酶、土壤蔗糖酶和土壤过氧化氢酶的影响,并得出结论。

Effects of Shading Treatments on Growth of Asimina triloba(L.) Dunal Seedlings

[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba （L） Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15：00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） content in leaves of A. triloba seedlings were highest comparing with those in other conditions.

加快林木种苗发展提高营林生产效益

我国的林业发展对我国的环境,能源供给都有着不可分割的关系,重视林业的发展,要注意到林木种苗的过程,林木种苗是林业发展的基础,是资源提供的保证,在林木种苗能够顺利发展的前提下,还是有很多的问题值得注意,要对林木种苗的重要性进行详细分析,提出几点有效提高营林生产效益的措施,给予相关人员一定的参考。

加快林木种苗发展提高营林生产效益

我国的林业发展对我国的环境、能源供给都有着不可分割的关系。林木种苗是林业发展的基础,是资源提供的保证,在林木种苗能够顺利发展的前提下,我们要对林木种苗的重要性进行详细分析,提出几点有效提高营林生产效益的措施,给予相关人员一定的参考。

Alkaloid variations in Catharanthus roseus seedlings treated by different temperatures in short term and long term

A study was conducted to investigate the effects of high temperature on variations of alkaloid metabolism in C. roseus seedlings in Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Heilongiang, China. 60-day-old C. roseus seedlings with 3-4 pairs of leaves were incubated in chambers with temperature of 30℃ and 40℃for short-term heat shock experiment and 20℃, 25℃ and 35℃ for long-term experiment. The contents of vindoline, catharanthine, vinblastine and vincristine in C. roseus leaves and root were checked at different temperatures in short term （1-6 h） and long term （1-16 d）. Results showed that under short-term heat shock, the contents of vindoline, catharanthine and vinblastine in leaves of the seedlings were higher at 40℃ than at 30℃, but after 6 h treatment, the contents of vindoline and catharanthine under the two temperatures came to the same level. Catharanthine was exclusively distributed in C. roseus roots and its content was increased by 40% after two hours incubation at 40℃, while increased slowly at 30℃ incubation and reached the highest value at 6 h. In the Long-term experiment, concentrations of monomeric alkaloids catharanthine and vindoline were higher at 20℃ than at 25℃ and had a sharp increase under the condition of 35℃. While for dimeric alkaloid, it showed that the higher the temperature, the earlier the peak value of vinblastine content appears. Vincristine had a continuous enhancement and attained 0.027 mg.g^-1 at 16th day under 35℃ condition which was higher than those in the other conditions. It was concluded that high temperature could promote the accumulation of different alkaloids in C. roseus and the accumulation characteristic is highly related to treatment time.

Effects of phosphorus and potassium addition on growth and nodulation of Dalbergia sissoo in the nursery

A study was conducted to test the influence of different inorganic fertilizers （phosphorous and potassium） on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung （soil： cowdung = 3：1）. Nodulation status （nodule number, shape, fresh weight, dry weight and color） in the roots and the plant growth parameters （length of shoot and root, collar diameter, fresh and dry weight of shoot and root） were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly （P〈0.05） in the soils amended with fertilizers in comparison to the control. The highest nodule number （62）, fresh （0.50 g） and dry （0.07 g） weights were recorded with the dose of PK at the rate of 160 kg/hm2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference （P〈0.05） among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm^2 fertilizer with soil and cowdung mixture （soil： eowdung = 3：1） is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level.

Effect of pre-sowing treatments on germination and initial seedling development of Albizia saman in the nursery

Albizia saman （Jacq.） F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed （at the distal end of the seed） （T4） provides the highest （50%） seed germination. The second highest germination （42%） was obtained for the seeds treated with immersion in cold water for 24 h （T1）. Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control （Ta）treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed （at the distal end of the seed） and T1 （Seeds immersed in cold water for 24 h） may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.

Treatments Comparison of Mineral and Bio Fertilizers in the Apple and Sour Cherry Organic Nursery

Maiden trees of apple cultivars ＇Topaz＇ and ＇Ariwa＇ grafted on M26 rootstock and of sour cherry cultivars ＇Debreceni Botermo and ＇Sabina＇ on mahaleb cherry （Prunus mahaleb L.） were fertilized with bioproducts such as： Fertigo-granulated manure, Micosat-microbial inoculum consisting of mycorrhizal fungi; Humus UP-an extract from vermicompost; Humus Active ＋ Aktywit PM-an extract from vermicomposts with PM （Positive Microorganism）; BioFeed Amin--a plant extract reinforced with amino acids; BioFeed Quality-a seaweed extract reinforced with humic and fulvic acids; Tytanit-titanium; Vinassa-molasses residue from yeast production; Florovit Eko-composed of many environmentally-friendly products. Control maidens were fertilized with mineral fertilizers containing mainly NPK. The maiden trees fertilized with the preparations Tytanit and Humus UP grew less vigorously and produced smaller increases in the length of lateral shoots than those fertilized with mineral fertilizers. On the other hand, bio preparations such as BF Amin, BF Quality, Micosat and Vinassa promoted tree branching and intensified the growth of lateral shoots, stimulating tree growth to a greater extent than the mineral fertilizers.

Effect of Seed Sizes on the Growth and Establishment of Seedlings of Sheanut Tree （Vitellaria paradoxa）

Seed size can influence germination, emergence and further development of plants to produce high yield. Therefore, pot trial was conducted to assess the effects of seed sizes on growth and establishment of sheanut tree seedlings （Vitellaria paradoxa） in tlae southern Guinea savanna of Nigeria. Seedlings produced from large sized seed had higher germination （80%） than those from medium （70%） and small （65%） sized seeds. Number of days to emergence of seedling from large-sized seed planting was 30 days, 49 days for small- and medium-sized seeds. Large sized seeds had higher N, P, K, Ca and Mg contents compared with small and medium sized seeds. Generally, seedlings from large sized seeds had about 1.5 times more leaves than medium sized seeds and about 2 times more leaves than small sized seeds at 8, 10, 12, 14 and 16 weeks after planting （WAP）. Seedlings from large sized seeds were taller and had larger stem girth （at 16WAP） than those from medium sized seeds. Variations in seedling growth from seed sizes could be of operational importance in nursery management as seeds can be sown according to size to improve uniformity. However, further studies to ascertain if the superior growth of seedlings from large sized seeds will lead to higher yield is recommended.

The Influence of Mycorrhizal Fungi on the Growth of Apple and Sour Cherry Maidens Fertilized with Different Bioproducts in the Organic Nursery

Apple/Malus x domestica cv. ＇Topaz＇/M26 and sour cherry cv. ＇Debreceni Botermo＇/Prunus mahaleb L. maidens were fertilized with different organic fertilizers and soil amendments in an organic nursery. A mycorrhizal inoculant, Micosat, was added to the non-fertilized control and to combinations fertilized with various bioproducts. Under assessment was the effect of nutrient delivery on the growth and development of maiden fruit trees focussing on tree height, thickness of the tree trunk, the number and the length of lateral shoots in each treatment combination. It was found that the introduction of mycorrhizal fungi into the soil without fertilizer application significantly improved the growth and development of apple and sour cherry maidens. Mineral fertilizer application （NPK） combined with mycorrhizal inoculation had a negligible effect on the above features. In the presence of bioproducts such as granular manure, Humus Active ＋ Aktywit PM, BF Amin, Vinassa and Florovit Eko, the mycorrhizal fungi were more biologically active than in the absence of these products.