中粒种咖啡光合特性的研究

自然状态下中粒种咖啡树冠外围向阳叶的光合速率及叶绿素 a/b 值均较树冠内部荫蔽叶大,但叶绿素含量和相等叶面积叶绿素的光谱吸收量却较小。与自然状态相同,人工遮荫叶的光合速率和叶绿素 a/b 值均较不遮荫的同龄叶小,但叶绿素含量和相等叶面积叶绿素的光谱吸收却较大。在低光照强度时,向阳叶和荫敝叶的光合速率部随光照强度的增加而提高,但光照强度超过一定值时,光合速率下降,即发生光抑制。发生光抑制的光照强度,向阳叶大于荫蔽叶。向阳叶光合作用的光饱和点和 DCPIP 光还原活性最大时的光照强度出都大于荫敝叶。呼吸作用和代表光呼吸的乙醇酸氧化酶活性也以树冠外围的向阳叶为大。中粒种咖啡的光合速率对低温敏感,在3万勒克司光照强度和高浓度 CO_2 条件下,光合作用的低温界限约在10℃。但温度高达35℃时,光合速率仍未见下降。     

海南岛低海拔小粒种咖啡分枝结果特性及与产量构成关系的研究

（１）海南岛低海拔小粒种咖啡具有明显的顶端优势，一级分枝的结果百分率和果节数极显和显高于二、三级分枝。在研究的４个品种中，一极分枝的干豆产量分别为二、三级分枝的１．６－５．６倍，达到极显和显的水平，是植株主要的结果枝条。（２）一级分枝和高产与其果节数量密切相关，它是经济产量构成因素的决定因素。因此低海拔小粒种咖啡可考虑采用多干整形，以提高其一级分枝的数量，增加植株的果节数，从而达到产。（３     

Genomic variability and plasticity of Pseudomonas causing coffee leaf spots in Minas Gerais state,Brazil

Foliar spots caused by Pseudomonas coronafaciens pv. garcae (Pcg), Pseudomonas amygdali pv. tabaci (Pat) and Pseudomonas cichorii (Pch) are major bacterial diseases that can reduce coffee production. However, little is known about the genetic diversity and molecular mechanisms underlying the pathogenicity to coffee plants of these bacteria. In this study, genome sequences of Pcg, Pat and Pch strains isolated from coffee plants in Minas Gerais state, Brazil, were used to assess their variability and plasticity, and compare their type III secretion system (T3SS) and apoplastic effector repertoires as well as tabtoxin biosynthetic/detoxification genes. Genomic diversity was found for all three phytopathogens, among which Pch possesses the highest number of exclusive proteins. The Pcg genome is the most stable whereas that of Pch is the most plastic, which is related to their host ranges. When compared with those of Pseudomonas syringae pv. tomato DC3000, hrp/hrc gene sequences are more conserved in Pcg and Pat than in Pch, which also possesses the smallest T3SS and the largest apoplastic effector repertoires. The only T3SS effector family common to all three pathogens is AvrE, suggesting that, as for other plant–Pseudomonas interactions, it may play a crucial role for pathogenicity towards coffee plants. Apoplastic proteins associated with maintaining the redox balance and degrading proteins/peptides not previously described as important in plant–bacteria interactions were found. Gain/loss of the tabtoxin biosynthetic cluster with retention of the antitoxin gene was observed, indicating that tabtoxin production is not a limiting factor for the occurrence of mixed infections.     

Variation among Colletotrichum gloeosporioides isolates from infected coffee berries at different locations in Vietnam

Isolates of Colletotrichum gloeosporioides associated with anthracnose disease on coffee berries in Vietnam were characterized by morphological and molecular methods. Random amplified polymorphic DNA (RAPD) and microsatellite-primered PCR (MP-PCR) analyses were employed to investigate the genetic variation among 38 and 51 isolates of C. gloeosporioides , respectively. According to both methods, the isolates mainly grouped in accordance with geographical origins. Higher genetic variation ( H  = 0·312 and 0·335) in the northern population of C. gloeosporioides than in the southern population ( H  = 0·261 and 0·186), according to the RAPD and MP-PCR markers, respectively, was indicative of a difference between the northern and southern populations. Moderate gene differentiation ( G st = 0·1) between populations from the north and the south was found. However, there was no differentiation between locations within the northern or southern populations, indicating significant gene flow. A four-gamete test indicated a high level of recombination, particularly in the south. The geographic differences may be explained by different histories of coffee cultivation in different parts of Vietnam. The symptoms caused by the Vietnamese isolates on both hypocotyls and green berries were less severe than symptoms caused by the reference CBD (coffee berry disease; Colletotrichum kahawae ) isolates originating from Africa.     

间作对咖啡和澳洲坚果根系形态、分布及养分累积的影响

为探明澳洲坚果与咖啡间作对地上部生长及地下部互作效应,为生产推广复合高效栽培模式提供理论依据,布置了咖啡和澳洲坚果间作盆栽实验,以二者分别单作为对照,分析植株的生长量、生物量、养分含量、根系形态以及土壤养分的差异.结果表明:(1)间作咖啡和间作澳洲坚果根干重、茎干重、单株总干重分别为40.86、50.38、148.34...     

河口县小粒种咖啡生产的农业气候条件区划与分析

在实地勘察、走访调查、资料收集与整理的基础上，依据生态环境相似性及生物资源开发近似性原则，采用气候相似性的原理建立回归方程，对河口县小粒种咖啡生产的农业气候条件进行(区划)分析，提出河口县小粒种咖啡产业发展的建议。     

德宏的咖啡选育种

介绍云南省德宏热带农业科学研究所小粒咖啡选育种研究的历程、成就、存在的问题及展望。     

Timber harvest,damage to crop plants and yield reduction in two Costa Rican coffee plantations with Cordia alliodora shade trees

Both model and field estimations were made of the damage inflicted to coffee plants due to the harvest of timber shade trees (Cordia alliodora) in coffee plantations. Economic analyses were made for different coffee planting densities, yields, and both coffee and timber prices.Damage due to tree felling and log skidding should not be a major limitation to the use of timber shade trees in coffee plantations. The timber price that would balance all discounted losses and benefits to zero, for scenarios with and without trees ranged between 8–20 US $/m³ (current overbark log volume at the saw mill yard is US$ 66/m³). There will be lower margins for coffee damage in high yielding plantations, specially in years of good coffee prices. Nevertheless, the use of timber shade trees is recommended even in these scenarios.     

Litter production and nutrient cycling in coffee (Coffea arabica) or cacao (Theobroma cacao) plantations with shade trees

The relative importance of N fixation, organic material inputs and nutrient inputs in litterfall, as justifications for including shade trees in plantations of coffee or cacao, is discussed. According to existing data, N fixation by leguminous shade trees does not exceed 60 kg.N/ha/a. However, these trees contribute 5,000–10,000 kg. organic material/ha/a.Comparisons are made between the leguminous shade tree Erythrina poeppigiana and the non-leguminous timber tree Cordia alliodora. The former, when pruned 2 or 3 times/a., can return to the litter layer the same amount of nutrients that are applied to coffee plantations via inorganic fertilizers, even at the highest recommended rates for Costa Rica of 270 kg.N, 60 kg.P, 150 kg.K/ha/a. The annual nutrient return in this litterfall represents 90–100 percent of the nutrient store in above-ground biomass of E. poeppigiana, and hence the consequences of competition with the crop should not be a serious limitation. In the case of C. alliodora, which is not pruned, nutrient storage in the tree stems, especially of K, is a potential limiting factor to both crop and tree productivity.It is concluded that, in fertilized plantations of cacao and coffee, litter productivity is a more important shade tree characteristic than N fixation.An early version of this review was presented at the CATIE-IUFRO meeting Los Arboles de Uso Multiple en Sistemas Agroforestales, June 1985, Turrialba, Costa Rica.     

Abandonement of coffee agroforests increases insect abundance and diversity

Shade coffee including many tree species is known to support generally high biodiversity. Due to low coffee prices on the world market, many farmers have abandoned their farms, thereby creating a new ecosystem type, which has attracted increasing interest for biodiversity conservation. Here we used pyrethrum knockdown samples to compare the arthropod community on coffee plants of six traditionally managed coffee agroforests with those of six abandoned coffee agroforests in coastal Ecuador. We investigated eight randomly selected coffee shrubs per site, six of them inside and two at the edge. All arthropods were identified to orders and beetles to morphospecies. We additionally sampled the vegetation to test for vegetation-mediated effects on the arthropod community. The number of arthropod individuals was higher in abandoned than managed coffee, driven by the abundance of Arachnida, Blattaria, and Heteroptera, and higher in the edge than in the centre of the abandoned agroforests. Higher arthropod abundance appeared to be closely related to arthropod diversity, as shown for beetles (r = 0.79, n = 96). Contrary to expectations, predator-prey ratios in managed agroforests was as high as in the abandoned ones. In conclusion, abandonment of coffee agroforests greatly encourages arthropod communities, in particular in the habitat edges, and therefore, should be considered in landscape management for conservation.