海南省火龙果产业发展形势及发展建议

热带水果是海南国际旅游岛建设的一张名片。火龙果种植是热带果树产业近年来发展的新、特、优、高项目。本文主要针对海南省火龙果产业发展形势,提出发展建议,为海南省火龙果产业发展提供指导。     

Changes in soil fertility and Striga hermonthica prevalence associated with legume and cereal cultivation in the Sudan savannah zone of Ghana

In the Sudano–Sahelian zones of West Africa, cultivated land is degraded due to reduced fallow periods and Striga hermonthica (Del.) Benth. infestation, and poses a serious threat to sustainable food production. To provide options for addressing these problems, we investigated the possibility of replacing the short fallow periods with food legume cultivation. We tested this in two farming communities within the Sudan savannah zone of Ghana. In the 1997 and 1998 cropping seasons, selected farmers within each community planted soybean [Glycine max. (L.) Merr.] or bambara groundnuts [Vigna subterranea (L.) Verdc.] on continuously cropped, Striga‐infested farmlands, whereas lands that were maintained under two or three years of bush fallowing were planted to millet [Pennisetum glaucum (L.) R. Br.] or sorghum [Sorghum bicolor (L.) Moench]. Analysis of soil sampled from 0–15 cm (plough layer) revealed that contents of major plant nutrients were inadequate to support long‐term crop production. Within each farming community, total nitrogen content at initial sampling showed significant negative correlation with the number of Striga seeds in the plough layer. Under legume cultivation, soil organic carbon content increased and the number of Striga seeds per square metre decreased in both communities from a mean value of 28 183 seeds m⁻² to 8185 seeds m⁻². Under cereal cultivation Striga seed density increased from 9383 seeds m⁻² to 16 696 seeds m⁻². The study provides evidence that introduction of food legume cultivation on farmlands with high S. hermonthica infestation as an alternative to bush fallow system could help achieve sustainable crop production in the Sudan savannah zones of sub‐Saharan Africa. Copyright © 2003 John Wiley & Sons, Ltd.     

Studies on the production of bambara groundnut ( Vigna subterranea) tempe

Bambara groundnut, an indigenous African legume, was subjected to fermentation by three strains of Rhizopus. One strain B. arrhizus could not ferment the substrate. Mycelial penetration and binding was good when strains NRRL 2710 ( R. oligosporus) and NRRL 1477 ( R. stolonifer) were used. Fermentation by both strains resulted in increases of pH, moisture, protein and fat while total carbohydrate decreased by 50%. Sensory evaluation showed that bambara groundnut tempes rated similar (p>0.5) in taste and texture and higher (p<0.05) in color and flavor than soybean tempe. Bambara groundnut would be an acceptable food product in the diet as a good protein supplement.     

Nutritional Components of Groundnut Seed Varieties and Their Damage by Khapra Beetle,Trogoderma granarium Everts

A laboratory experiment was carried out to determine the response of six groundnut varieties to infestation by larvae of Trogoderma granarium Everts (Coleoptera: Dermestidae) and their nutritional constituents. The improved groundnut varieties used included SAMNUT 10, RMP-91, SAMNUT 19, SAMNUT 23, EX-DAKAR and RRB. The crude fat content varied significantly among the varieties from 32.7% to 53.1% in EX-DAKAR and RRB, respectively. The seed varieties were not significantly different in crude protein, ash and moisture content. The moisture content ranged between 6.6% and 8.9% in EX-DAKAR and SAMNUT 19 varieties, respectively. The crude protein content ranged between 19.7% and 31.3% in SAMNUT 19 and EX-DAKAR, respectively. The ash content varied between 3.0% and 7.4% in RRB and RMP-91 varieties, respectively. The results showed that the seeds were attacked by the 4th instar larvae of T. granarium as indicated by percentage seed weight damage, seed weight loss and dust production. SAMNUT 10 variety had the least seed damage of 33.1%, 41.4% and 43.7% in 1 month, 2 and 3 months post-infestation. In view of the damage, it was evident that SAMNUT 10 variety had the least percent seed damage and loss suggesting the possible inclusion of the variety in breeding programme against the insect pest.     

采收期对火龙果贮藏期间活性氧代谢的影响

[目的]探讨不同时期采收的火龙果在贮藏过程当中活性氧代谢变化的规律。[方法]以白玉龙火龙果为试材,研究了不同采收期对火龙果常温贮藏过程中活性氧代谢的影响。[结果]采收越早（花后21 d）,火龙果的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性越高,出现活性峰的时间越早,丙二醛（MDA）、前期的O2-.含量及膜透性较低;采收过晚（花后29 d）,O2-.含量显著增高,贮藏前期SOD、POD活性较低,贮藏后期POD活性较高,CAT活性较低,MDA和膜透性较大。适时采收（花后25 d）,SOD、POD、CAT活性、MDA含量和膜透性位于二者之间,但显著降低了火龙果中O2-.含量。[结论]火龙果花后25 d采收,可以显著降低O2-.的积累,同时保护酶系统也维持较高的活性。     

火龙果的冷却方式选择

[目的]研究火龙果的最佳冷却方法。[方法]首先进行不同终压（550、600及650Pa）的真空预冷、不同水温（0、1．5及3℃）的水冷及2m／s风速的强制通风（4℃）试验,然后,从每种试验中选择最优组进行比较,从中选择最适合火龙果的冷却方式。[结果]真空预冷最低只能将火龙果降到10℃左右;强制通风虽能把火龙果降到5℃以下,但时间过长,需要4～5h;冷水温度为0℃时,火龙果的温度降低最快,1h可降到5．5℃。[结论]火龙果的最佳冷却方式是0℃水冷。     

A new stem nematode associated with peanut pod rot in China: morphological and molecular characterization of Ditylenchus arachis n. sp. (Nematoda: Anguinidae)

Surveys conducted in peanut production areas of China revealed peanut pod rot in several fields in Shandong and Hebei Provinces, China. A large quantity of an unknown stem nematode was isolated from the hulls and seeds of peanuts, herein described as Ditylenchus arachis n. sp. The new species is characterized by a combination of the following features: lateral lip sectors distinctly projected, stylet delicate, 8·4–10 μm in length, six lines in the lateral field, tail elongate–conoid, bursa covering about 68–86% of tail length. Pathogenicity tests showed that D. arachis n. sp. could infect peanut (Arachis hypogaea), but not sweet potato (Ipomoea batatas) or potato (Solanum tuberosum). Morphologically, D. arachis n. sp. appears closest to D. africanus, D. myceliophagus and D. destructor, but can be differentiated based upon a combination of morphological characteristics, host preference and molecular sequence data. The results of the phylogenetic analysis, based on 18S rDNA, the D2–D3 expansion region of 28S rDNA, and the ITS1–5·8S–ITS2 region, confirmed its status as a new species. A sister relationship with D. destructor was appointed, rather than with its ecologically very similar congener D. africanus.     

因山活水,游乐温泉——以周公山御泉湾龙溪休闲山庄景观设计为例

温泉休闲逐渐成为当代人首选的娱乐活动之一。以周公山御泉湾龙溪休闲山庄景观设计为实例,从其规划功能分区和设计思路以及手法,阐述了以温泉为主体,以温泉为体、园林为用、渐次山水、生态游乐为理念进行温泉休闲山庄设计的重要构想和手法。     

30％龙灯福连悬浮剂对冬枣主要病害的防治效果研究

[目的]研究30％龙灯福连悬浮剂对冬枣抗病性的影响。[方法]试验设30％龙灯福连悬浮剂和常规真菌药剂2个处理,以喷施清水为对照,研究啧施30％龙灯福连悬浮剂对冬枣主要真菌病害的防治效果。【结果】喷施杀菌剂30％龙灯福连悬浮剂,冬枣树褐斑病、青癍病和锈病的病叶率分别为0～0．43％、0．55％～1．12％、0,校正防效分别为95．92％～100％、98．15％～99．11％、100％,与对照差异显著。[结论]30％龙灯福连悬浮剂对褐斑病、青斑病、枣锈病的病害防治效果显著,而且省工、省时,可作为防治冬枣真菌性病害药剂。     

我国花生抗病性研究进展

综述了近年来我国在花生抗病性分子标记、抗病性遗传规律、抗病机理、抗病种质发掘等方面取得的研究进展.展望了分子标记技术在花生上的应用前景.