粤北小红栲林的群落特征   总被引：6，自引：1，他引：6  

张木明  陈北光  苏志尧 《华南农业大学学报》2001,22(3):9-12

用样方取样法对粤北小红栲 (Castanopsiscarlesii)林进行调查 ,并对粤北小红栲林结构特征进行了研究 结果表明 ,粤北小红栲林的植物种类繁杂 ,在 6 30 0m2 的样方面积中有维管束植物 184种 ,隶属于 5 9科 12 3属 优势科为壳斗科、樟科、茶科等 ;植物区系具有明显的热带亚热带性质 ;区系的地理成分以泛热带分布和热带亚洲分布的属为主 ,是广东植物区系的重要组成部分 ,隶属于华南省中的粤北 -闽西南亚省 ,归属于东亚植物区华夏植物界 粤北小红栲林植物的生活型谱以中高位芽植物和小高位芽植物占优势 粤北小红栲林的成层现象明显 ,可划分为乔木层、灌木层、草本层 ,乔木层可再划分为 2个亚层 乔木、灌木的植物种类较多 ,草本植物和层间植物种类较少 粤北小红栲林的林分密度为 3144株·hm 2 ,林木的平均距离为 1.69m  相似文献   

不同基因型大豆冠层冷温现象的研究   总被引：2，自引：0，他引：2  

李永平  王长发  赵丽 《西北农林科技大学学报(自然科学版)》2007,35(11):80-83

为了解不同基因型大豆冠层冷温现象,应用红外测温仪对大豆冠层温度进行了长期观测,并测定了大豆生育期的蒸腾速率和净光合速率,以及大豆主茎功能叶片的可溶性蛋白质、丙二醛含量。结果表明,不同基因型大豆品种冠层温度存在着明显的分异现象,其中NF58与秦豆8号(对照)的冠层温差最高值为-1.47℃,最低值为-0.02℃,均低于基准线(0℃线,下同),为冷型大豆;94101与秦豆8号(对照)的冠层温差最高值为1.48℃,最低值为0.02℃,均高于基准线,属暖型大豆,且冷型大豆NF58具有较强的生理活性,表现在叶片功能期较长,蒸腾速率和净光合速率较高,蛋白质含量较高,丙二醛(MDA)含量较低,说明在大豆品种选育中以冷温材料为亲本或在育种中以冷温作为目标性状之一值得重视。  相似文献   

5个烤烟新品种与云烟87的比较研究     

郭东锋  姚忠达  舒俊生  吴克松  周初跃  杜丛中  王忠平  罗应坤  李兰周  崔宇翔  杨焕文  李佛琳 《云南农业大学学报(自然科学版)》2011,26(Z1):98-104

 为筛选出适应丽江地区烤烟种植区优质、适产、抗病性强的新品种,在2009～2010年于丽江市永胜县开展了以云烟87为对照,XYN87,云烟113,云烟114,云烟115,T29共5个新品种的区域试验。进行了生物学性状、抗病性、经济性状等观测分析。结果表明：在5个供试品种中,T29的经济性状最好,产量为3256.35kg/hm2;在抗病性上云烟113最优,白粉病病株率3.75%为最低;从化学成分上看,云烟115与T29的糖碱比分别为10.78和9.31,化学成分最协调。两年的适应性研究结果的主成分分析法综合成分得分T29为1.07674,表现最佳。  相似文献   

宝珠梨疫腐病病原菌研究   总被引：1，自引：0，他引：1  

董文汉  何永宏  赵永安  刘云龙 《云南农业大学学报(自然科学版)》2002,17(2):143-146

 宝珠梨疫腐病是云南省的一种新记录病害,其病原菌为恶疫霉Phytophthora cactorum (Lebert et Cohn) Schrot.适宜恶疫霉分离培养的培养基是番茄汁培养基、V8汁培养基和PDA培养基。适宜恶疫霉生长的pH值范围在3～10之间,最适pH值为5～6,适宜生长的温度范围为在10～30℃之间,最适生长的温度为20～25℃. 恶疫霉对果糖、麦芽糖、蔗糖等碳源的利用好于其它碳源,对酵母膏、天门冬酰胺、牛肉膏等氮源的利用好于其它氮源。  相似文献   

鸭舌草生物学特性及治理对策   总被引：3，自引：0，他引：3  

吴竞仑  周恒昌 《江苏农业学报》2002,18(2):94-98

对稻田恶性杂草鸭舌草的植物学和生物学特性及其对水稻产量的影响等进行了室内外系统研究。结果表明 ,鸭舌草分布广泛 ,有较长的生理休眠期 ;种子在 1cm土层内萌发最好 ,在 2～ 4cm土层内则出苗极少 ;土壤饱和水分条件有利于种子萌发 ;生长发育的最适温度为 2 0～ 2 5℃ ,土壤水分饱和或薄水条件下生长最好 ,肥料充足则生长迅速 ;鸭舌草在直播稻田、抛栽稻田和移栽稻田均有明显的出草高峰 ;1m2 定植鸭舌草 80株 ,稻、草共生 4 0d水稻减产 14 0 % ,全生育期稻、草共生 ,水稻减产达 19 5 % ;鸭舌草与水稻竞争的临界密度为 1m2 6 0株 ,水稻减产达10 0 %以上。生产中宜采取水旱轮作、减少追肥、科学治虫、保护天敌、促进水稻早生快发 ,并以群体优势控草、稻田养鸭 ,以及应用除草剂乙苄或苯噻酰苄等综合措施来治理鸭舌草  相似文献   

甘蓝型细胞质雄性不育杂交油菜亲本配合力与遗传力效应研究          下载免费PDF全文

田广文  徐爱遐  金平安  李文华  马长珍 《西北农业学报》2005,14(5):14-18

选用甘蓝型油菜5个细胞质雄性不育系和5个优势恢复系,采用不完全双列杂交,配制25个杂交组合,对25个组合的10个主要数量性状进行了配合力和遗传力分析,结果表明,双亲的一般配合力效应依次对杂交F1代的一次有效分枝数、产量、株高、单株有效角果数和千粒重有明显影响;特殊配合力效应对二次有效分枝数、单株有效角果数和产量的表现有较大影响;5个不育系中A1的一般配合力效应值最高;5个恢复系中R4一般配合力效应值最高;产量特殊配合力好的组合是A5不育系×R1、A4不育系×R4.遗传力分析表明,产量、一次有效分枝数、单株有效角果数、株高和千粒重等的遗传力较高.  相似文献   

骆驼蓬提取物对玉米生长的影响   总被引：2，自引：0，他引：2  

刘建新  赵国林 《西北农业学报》2004,13(3):14-17

以不同浓度的骆驼蓬提取液浸泡玉米种子20h,通过室内培养和田间试验研究了对玉米生长的影响。结果表明,经一定浓度骆驼蓬提取液浸种处理的玉米,根系和地上部生长量增加,根苗比增大;叶绿素和叶片可溶性蛋白质含量增加,硝酸还原酶活性提高,而过氧化氢酶活性降低。田间试验表明,0.1g/mL和0.2g/mL浓度浸种处理明显促进玉米株高、茎粗增加,穗粒数和千粒重提高,产量增幅分别达12.68%和11.48%。  相似文献   

Assessment and selection of fungal antagonists against Rhizoctonia solani          下载免费PDF全文

Grosch R　 Faltin F　 Lottmann J　 Kofoet A　 Berg G 《浙江大学学报(农业与生命科学版)》2004,30(4):393-393

The soil-borne pathogen Rhizoctonia solani Kühn (teleomorph, Thanatephorus cucumeris [A.B. Frank] Donk) is worldwide responsible for serious damage of many economically important agricultural and horticultural crops. Control of Rhizoctonia diseases is difficult because this pathogen survives for many years as sclerotia in soil or as mycelium in organic matter under numerous environmental conditions. Furthermore, the pathogen has an extremely wide host range. To date, no effective con…  相似文献   

Phytochemical and antioxidant properties of selected fig (Ficus carica L.) accessions from the eastern Mediterranean region of Turkey     

Oguzhan Çalişkan  A. Aytekin Polat 《Scientia Horticulturae》2011

Fig has been a typical fruit component of the health-promoting Mediterranean diet for a very long time. Phytochemical characters and antioxidant capacity of green-, yellow-, brown-, purple-, and black-fruited fig (Ficus carica L.) accessions were investigated. In this study, total phenolics (TP), total anthocyanins (TA), fructose (FRUC), glucose (GLUC), sucrose (SUC), and variables (such as L*, a*, C*, and hue°) describing fruit skin colors were examined. Also, the antioxidant capacity (TAC) of fig fruits was determined by the ferric reducing antioxidant power (FRAP) assay. Antioxidant capacity was significantly correlated with the polyphenol and anthocyanin (r = 0.74 and 0.63, respectively) contents of fruits. Black fig accessions had the highest TAC (range of 7.9–16.1, mean 12.4 Fe²⁺ mmol/kg FW), TA (range of 32.3–356.0, mean 128.4 μg cy-3-rutinoside/g FW), and TP content (range of 69.1–220.0, mean 118.9 mg GAE/100 g FW). These black-fruited accessions had 2-fold greater TAC, 15-fold greater TA, and 2.5-fold greater TP than green and yellow fig accessions. However, the FRUC, GLUC, and SUC content of brown and purple fig accessions were higher than those of other color groups. The predominant sugars present were fructose (∼56%) and glucose (∼43%), as determined by HPLC.  相似文献   

Resolving conflicts between butterfly host resource abundance and genet population size estimates for a vegetatively spreading, threatened grassland legume     

Paul M. Severns  Mark V. Wilson 《Biological conservation》2011,(3):1152-1158

Population size estimates are an integral part of rare plant conservation, but common abundance measurements such as cover and ramet number may not accurately index genet population size for vegetatively spreading species. Population monitoring of Kincaid’s lupine (threatened species) populations occurs through genet-anonymous leaf cover and raceme counts despite extensive, non-adventitious rhizome growth. While the current monitoring scheme provides important resource abundance measurements for the endangered Fender’s blue butterfly, whose larvae feed on Kincaid’s lupine leaves, the methods are not appropriate for estimating lupine genet number. Major axis regression revealed well supported statistical relationships between cover, raceme, and plantlet (a measurement of modular plant growth) density within six study patches (n = 3 populations) of Kincaid’s lupine (R² > 0.90) and when all patch data were combined (R² > 0.91). Genet population size estimates from genotype only data with ACE (an estimator used to infer species richness) were similar to estimates derived from a combination of plantlet density and genet to plantlet ratios (genotype derived) in small, more thoroughly genotyped lupine patches. However, genet number estimates from ACE were 3–5-fold greater in less intensely genotyped patches. Genet-anonymous plant abundance measurements, such as cover, can be used to estimate genet number in populations of vegetatively spreading plants provided they are calibrated with a unit of modular plant growth. Calibration of vegetative measurements, consistency of between population relationships, and closer scrutiny of highly supported statistical models may be necessary to develop more pertinent monitoring methods for rare, vegetatively spreading plants.  相似文献