拟南芥新型脂转移蛋白AtDHyPRP1的亚细胞定位及其对灰霉菌的抗性

通过遗传转化技术研究了拟南芥脂转移蛋白AtDHyPRP1在细胞中的定位及其对真菌病原体的抗性。采用PCR方法从拟南芥Ws生态型克隆了AtDHyPRP1基因,构建产生pRI101-AN-AtDHyPRP1植物双元表达载体和pCAMBIA1302-AtDHyPRP1-GFP融合表达载体,经农杆菌介导的叶盘和浸花法得到烟草和拟南芥转基因植株。AtDHyPRP1基因能够明显增加烟草对灰霉菌的抗性,转AtDHyPRP1烟草叶片的被侵染部位有大量H2O2积累,激光共聚焦显微观察发现AtDHyPRP1蛋白定位于细胞表面。说明AtDHyPRP1蛋白在合成后被分泌到细胞外执行特殊的功能,与植物抗病防御机制有关。     

杉木萌芽林林冠下营造细柄阿丁枫与木荷的生态效益的研究

 本文通过对杉木萌芽林林冠下营造中亚热带常见乡土阔叶树种——细柄阿丁枫与木荷后,形成的杉阔混交林的两年定位观测研究,结果表明：杉木萌芽林改造成细柄阿丁枫杉木混交林与木荷杉木混交林后,林分水源涵养功能增强,土壤肥力提高,林内小气候得到改善,林分抗御火灾能力增强。杉木林冠下营造乡土阔叶树种是改良杉木林生态环境质量,科学经营杉木低产林的有效生物措施之一。     

Effects of cutting and rainfall pattern on resprouting vigour and growth of Erica arborea L.

Abstract. This study analyses the effects of recurrent cutting and rainfall pattern on sprout and genet growth in the resprouting shrub Erica arborea. Three different intervals between consecutive clear-cutting events were applied: 30, 5 and 2 yr. Above-ground genet biomass after 2 yr of treatment application was correlated with burl size and decreased with increasing recurrence of cutting, indicating that more than 5 yr were needed to re-establish the resprouting potential of genets. The effect of rainfall on growth was evaluated through the correlations between sprout RGR and several variables related to the rainfall pattern at different regeneration stages. The effect of the rainfall pattern on sprout RGR was dependent on the regeneration age, suggesting that water availability becomes more limiting after two years of regrowth.     

番红花侧芽中的新蒽醌化合物

从番红花（ＣｒｏｃｕｓｓａｔｉｖｕｓＬ．）侧芽的氯仿萃取部分分离到４个蒽醌类化合物（Ⅰ、Ⅱ、Ⅲ、Ⅳ）：Ⅰ和Ⅱ分别为大黄素和２羟基大黄素;Ⅲ和Ⅳ为两个新的蒽醌类化合物,分别为１甲基３甲氧基８羟基蒽醌２羧酸和１甲基３甲氧基６,８二羟基蒽醌２羧酸,通过光谱和化学方法确定了它们的化学结构。     

Evaluation of biological seed treatments in combination with management practices for the control of Fusarium dry rot of potato

Seed-borne diseases of potato represent a significant constraint to potato production in the US. The use of an effective fungicide in combination with good management practices during cutting and storage, prior to planting, is essential to reducing disease. The efficacy of two biocontrol agents (Bacillus subtilis and Trichoderma harzianum), and a commercially formulated mixture of the chemicals fludioxonil plus mancozeb, applied as seed treatments in combination with different management practices, were evaluated over two years for the control of seed piece decay and sprout rot caused by Fusarium sambucinum. Treatments were made 10 days prior to planting and at planting, and tubers were re-stored at either 18 °C and 95% RH with forced air ventilation at 5950 l min⁻¹ (optimal conditions), at 25 °C in the dark without ventilation (sub-optimal), or not stored at all prior to planting. Seed piece and sprout health were evaluated in vitro and agronomic impacts evaluated in field experiments. Results showed that the biological control agents B. subtilis and T. harzianum provided good control of sprout rot and seed piece decay caused by F. sambucinum, when seed was re-stored under optimal conditions or not re-stored at all. Under optimal conditions, treatment with B. subtilis reduced sprout rot and seed piece decay on average by 66% and 84%, respectively. Treatment with T. harzianum reduced sprout rot and seed piece decay on average by 70% and 81%, respectively. Treatment with fludioxonil + mancozeb reduced sprout rot and seed piece decay under both re-storage regimes. Under optimal conditions, disease incidence and severity was reduced on average by 81% and 97%, respectively. Neither biological control agent reduced seed piece decay incidence under either re-storage regime compared to the untreated controls.     

Population dynamics of four understorey shrub species in beech forest

Question: In the population dynamics of four understorey shrub species (Hp, Hydrangea paniculata Sieb, et Zucc.; Lu, Lindera umbellata Thunb. var. membranacea (Maxim.) Momiyama; Ms, Magnolia salicifolia (Sieb, et Zucc.) Maxim.; Vf, Viburnum furcatum Blume ex Maxim.), (1) What is the relative importance of seedling regeneration versus vegetative growth? (2) Can these shrubs persist stably for a long time in the understorey? (3) What kind of variation in demographic features is observed among these shrubs? Location: 780m a.s.l., north‐eastern Japan. Methods: Population dynamics were analyzed by using stage‐classified matrix models. Models were mainly constructed from five years stem‐census data, including current‐year seedlings and sprouts. Results: Current‐year sprouts emerged every year in every species. Current‐year seedlings emerged every year in Lu and Vf, but densities were very low. In every species, population growth rate (A) was close to the equilibrium value 1.0 and no statistical difference was found among species. The stable stage‐distribution predicted from the matrix model was similar to the observed distribution for Lu, Ms and Vf, but much different for Hp. Elasticity matrix was also similar among Lu, Ms and Vf, but was quite different for Hp. Conclusions: Lu, Ms and Vf were considered as climax shrubs that can regenerate and maintain their population stably in the understorey, even if canopy gaps form infrequently. Hp is a pioneer shrub that require more frequent formation of canopy gaps for long‐term persistence in the understorey.     

Genetic mapping of QTLs conditioning soybean sprout yield and quality

Soybean sprouts have been used as a food in the Orient since ancient times. In this study, 92 restriction fragment length polymorphism (RFLP) loci and two morphological markers (W1 and T) were used to identify quantitative trait loci (QTLs) associated with soybean sprout-related traits in 100 F₂-derived lines from the cross of ’Pureunkong’×’Jinpumkong 2’. The genetic map consisted of 76 loci which covered about 756 cM and converged into 20 linkage groups. Eighteen markers remained unlinked. Phenotypic data were collected in 1996 and 1997 for hypocotyl length, percentage of abnormal seedlings, and sprout yield 6 days after germination at 20°C. Hypocotyl length was determined as the average length from the point of initiation of the first secondary root to the point of attachment of the cotyledons. The number of decayed seeds and seedlings, plus the number of stunted seedlings (less than 2-cm growth), was recorded a s abnormal seedlings. Seed weight was determined based on the 50-seed sample. Sprout yield was recorded as the total fresh weight of soybean sprouts produced from the 50-seed sample divided by the dry weight of the 50-seed sample. Four QTLs were associated with sprout yield in the combined analysis across 2 years. For the QTL linked to L154 on the Linkage Group (LG) G the positive allele was derived from Pureunkong (R ² = 0.19), whereas at the other three QTLs (A089 on LG B1, A668n on LG K and B046 on LG L) the positive alleles were from Jinpumkong 2. QTLs conditioning seed weight were linked to markers A802n (LG B1), A069 (LG E), Cr321 (LG F) and A235 (LG G). At these four markers, the Jinpumkong allele increased seed weight. Markers K011n on LG B1, W1 on LG F and A757 on LG L were linked to QTLs conditioning hypocotyl length; and Bng119, K455n and K418n to QTLs conditioning the abnormal seedlings. The QTLs conditioning sprout yield were in the same genomic locations as the QTLs for seed weight identified in this population or from previously published research, indicating that QTLs for sprout yield are genetically linked to seed-weight QTLs or else that seed-weight QTLs pleiotropically condition sprout yield. These data demonstrate that effective marker-assisted selection may be feasible for enhancing sprout yield in a soybean. The transgressive segregation of sprout yield, as well as the existence of two QTLs conditioning greater than 10% of the phenotypic variation in sprout yields provides an opportunity to select for progeny lines with a greater sprout yield than currently preferred cultivars such as Pureunkong. Received: 23 August 2000 / Accepted: 23 January 2001     

Effect of root competition and shading on resprouting dynamics of Erica multiflora L.

Abstract. Resprouting from underground structures is one of the main regeneration strategies of Mediterranean shrubs after aerial biomass disturbance such as fire or clear-cutting to reduce fire risk. In order to study the effect of root competition and shading (simulated shoot competition) on Erica multiflora, growth, morphology, flowering performance and sprout size variability during resprouting, a factorial field experiment was conducted in which neighbours around target plants were eliminated and plants were shaded with mesh for two years. Root competition reduced sprout recruitment and sprout density (number of sprouts per unit stump area) more strongly than did shading. The negative effect of root competition on sprout biomass was constant with time, while the reduction due to shading increased with time. There was an interaction between root competition and shading on the biomass of sprouts 22 months after treatment: genets without root competition and shading were four times larger than in any other treatment. Both shading and root competition also decreased percentage branching but did not modify maximum sprout height. Only shading decreased the leaf/shoot biomass ratio and the percentage of flowering genets. One year after resprouting, root competition counteracted the effect of shading on inducing sprout biomass variability within the genet because it decreased sprout density. 22 months after treatment, sprout biomass variability was not affected by any main effect. The results suggest that competition among sprouts within the genet is asymmetric. However, shading by genet neighbours may not always increase sprout biomass variability if root competition is also severe.     

天童几种常绿阔叶林优势种在砍伐后萌枝更新的初步研究

对以萌生方式形成的木荷、石栎、苦槠、栲树、米槠植株的根桩和萌枝状况进行了调查及测量。结果显示各种类萌枝数的大小顺序是:木荷>苦槠>石栎>米槠>栲树;结合萌枝状况可以推断萌枝能力的大小顺序应该是:木荷>苦槠>石栎>栲树>米槠。砍伐对木荷、石栎、苦槠、栲树、米槠萌芽更新都会造成影响,对栲树、米槠影响更大,而对木荷、石栎、苦槠影响较小。从植物萌生角度来说,这是形成研究地区大面积的以木荷、石栎、苦槠为优势种组成的次生灌丛的主要原因。     

Forest fire in the central Himalaya: climate and recovery of trees

 A forest fire event is influenced by climatic conditions and is supported by accumulation of fuel on forest floor. After forest fire, photosynthetically active solar radiation was reduced due to accumulation of ash and dust particles in atmosphere. Post-fire impacts on Quercus leucotrichophora, Rhododendron arboreum and Lyonia ovalifolia in a broadleaf forest were analysed after a wild fire. Bark depth damage was greatest for L. ovalifolia and least for Q. leucotrichophora. Regeneration of saplings was observed for all the tree species through sprouting. Epicormic recovery was observed for the trees of all the species. Young trees of Q. leucotrichophora (<40 cm circumference at breast height) were susceptible to fire as evident by the lack of sprouting. Under-canopy tree species have a high potential for recovery as evident by greater length and diameter of shoots and numbers of buds and leaves per shoot than canopy species. Leaf area, leaf moisture and specific leaf area were greater in the deciduous species, with few exceptions, than in evergreen species. Received: 26 July 1995 / Revised: 1 March 1996 / Accepted: 9 September 1996