‘热引19号’坚尼草选育研究报告

1998年从澳大利亚引入坚尼草TD58(Panicum maximum‘TD58')后,相继完成适应性评价、品种比较试验、区域试验和生产试验,2007年选育而成‘热引19号'坚尼草(P.maximum'Reyin NO.19')。结果表明:该品种年均干草产量达21753.02 kg·hm~(-2),种子年均产量为800.05 kg·hm~(-2),营养价值适中,且耐低温、耐荫、耐旱、花期晚,综合性状均优于对照品种,是适合于我国南方热带亚热带地区推广种植的牧草新品种。     

供磷水平对‘热研5号'柱花草-根瘤菌共生体系的影响

为研究不同供磷水平对热研5号柱花草(Stylosanthes guianensis‘Reyan No.5')-根瘤菌共生体系的影响,利用水培试验对接种7株不同根瘤菌的柱花草进行3个磷浓度的处理,通过对柱花草干重、植株含氮量、根瘤数、固氮酶活性的测定及分析确定磷对共生体系的影响。结果表明:低磷不利于柱花草及根瘤菌共生体系的生长;菌株YM11-1,FS3-1-1在高磷时固氮促生效果最佳,菌株LZ3 2,RJS9-2,BS1-1,CJ1则在中等磷条件下固氮促生效果最佳,磷对菌株PN13-3的影响不大。     

贫困村民自己运作的小额信贷扶贫

小额信贷扶贫到户不同于传统的小额信贷方式,该种贷款方式完全由村民自己运作,贷款对象面向贫困农户,运作成本低,还贷率达100%.文中简要介绍了小额信贷扶贫的运作模式及其主要特点.     

Palms in Indigenous and Settler Communities in Southeastern Ecuador: Farmers’ Perceptions and Cultivation Practices

Most palms used in agroforestry systems are exploited from wild stands or are only occasionally cultivated, while only a few palms have been domesticated. In this study we investigated how socio-economic factors and people's perceptions of changes in palm use and availability, influenced palm cultivation among indigenous Shuar and mestizo settlers in south-eastern Ecuador. We also looked at how different uses of palms influenced which species they cultivated. Our results showed that perceptions of declining palm availability in combination with heavy reliance on palm products was positively related to palm cultivation. Hence, cultivation was more common in more remote villages where alternative products were hard to get. In addition, palm cultivation was more common among wealthier people and among indigenous people than among recent settlers. This points to a limiting role of assets such as land and to the importance of history and culture with regard to cultivation. It was not possible to identify any single palm use as the primary reason for cultivating a species, but the more uses a species had, the more likely it was to be cultivated. These findings have important implications for development projects that promote cultivation of palms and other long-lived tree crops. They illustrate how market access and lack of necessary assets may undermine cultivation of native species even though these are regarded as important resources.     

Factors affecting a sheep vegetation management system in British Columbia, Canada

A silvopastoral agroforestry system involving sheep is an important silvicultural issue. We examined the factors that affect the continuation or discontinuation of sheep vegetation management (SVM) in British Columbia. A questionnaire was used to conduct interviews with a randomly selected sample of contractors and farmers who were involved in SVM in British Columbia (BC). Based on a stepwise discriminant analysis, we found that the profitability of SVM, and the practitioners' commitment (number of ewes owned by the farmer or contractor), experience (number of years the farmer or contractor has practiced SVM on public lands in BC) and trust or confidence (number of years the farmer or contractor has consistently worked for the landlord) contributed to the farmer's or contractor's continuation or discontinuation of SVM practice. The factors we defined seemed to be validated (corroborated) by a complex of determinants voiced by various experts concerning the relationship between SVM and the forestry economy in BC, the scale of sheep farming in BC, the relative absence of an agricultural infrastructure to support sheep farming in BC, and the continuity of SVM from year to year. Further investigation into these factors and others is required to advance our understanding of SVM in British Columbia. This revised version was published online in June 2006 with corrections to the Cover Date.     

女诗人薛涛与望江楼公园

以纪念女性为主的园林是中国历史园林的特殊类型,理清其营建的动因和经验,是传承中国园林文化的重要补充。纪念唐代女诗人薛涛的望江楼公园,其兴建、发展、造景等方面与薛涛的人生经历、个性品行紧密结合。基于历史文献梳理和园林空间分析,剖析了望江楼公园的发展变迁历程,归纳了针对薛涛的园林景观的纪念性造景手法,从遗迹、植物、建筑、活动等方面分析了女诗人薛涛与望江楼公园之间相辅相成的关系。     

The effect of cattle foot traffic on soil compaction in a silvo-pastoral system

In India, small farmers have generally found that the growing of eucalypts as a cash crop provides poor returns, and many have reverted to growing annual crops. Farmgate prices have been much lower than retail prices, due to the existence of middlemen, and retail prices have fallen to lower levels than expected as markets have become saturated. This article describes the situation in eastern Gujarant, where farmers sold their eucalypts directly to buyers at prices close to those in organised wood markets. An important reason for this unusual situation is the absence in Gujarat of controls on eucalyptus sales, which has helped producers to avoid dependence on rent-seeking intermediaries. The survey shows that growing eucalyptus can be a profitable activity for small farmers, given the right circumstances.     

香榧体细胞胚发生、发育的形态与细胞学观察

将香榧(Torreya grandis‘Merrillii’)的未成熟合子胚置于SH+0.1 mg·L-1 NAA+500 mg·L-1AC+3%蔗糖+0.5 g·L-1 Gln培养基上暗培养45 d,诱导产生半透明颗粒状胚性愈伤组织;将胚性愈伤组织转入SH+20 g·L-1 PEG+10 mg·L-1 ABA培养基中暗培养3个月诱导体细胞胚。采用碘—碘化钾染色和石蜡切片技术对体胚起源、形态发育与细胞组织学进行了观察。结果表明:胚性愈伤组织起源于合子胚胚轴表皮或皮层细胞的对称分裂。胚性愈伤组织含有两类细胞,一种是细胞质浓厚、细胞核大、体积小的圆形胚性细胞,另一种是高度液泡化拉长的细胞。胚性愈伤组织包含由这两种细胞构成的原胚团Ⅰ、原胚团Ⅱ和原胚团Ⅲ,以及一些游离细胞。原胚团Ⅲ在无植物生长调节剂的SH基本培养基上形成原胚,原胚接入成熟培养基,历经球形、棒状、心形、鱼雷形胚后发育成子叶胚。将子叶胚转入萌发培养基后胚根伸长,胚芽发育长出针叶,形成完整的再生植株。同时在离体培养中合子胚胚柄处退化的裂生多胚也能重新发育形成胚体。在初生体胚发育过程中表面常伴有次生体细胞胚的形成。     

竹业在社会主义新农村建设中的作用及应注意的问题——以龙游县为例

以龙游县为例,分析了竹业富民、生态环境保护、乡村绿化和景观改善、农村剩余劳动力就地安置、农民素质提高等竹业在社会主义新农村建设中的作用,提出了竹林立地生产力衰退、竹产业链环节的利益分配、竹业生产中的环境恶化等方面的现实问题及解决这些问题的建议。