咖啡叶片DNA提取方法的比较研究

以咖啡成熟叶片为材料,进行多种DNA提取方法比较研究,并通过琼脂糖凝胶电泳和紫外分光光度计检测所提的DNA样品。结果表明,CTAB改良Ⅰ和CTAB改良Ⅱ均可用于咖啡叶片的DNA提取,尤其是CTAB改良Ⅱ法,提取的DNA产量较CTAB改良Ⅰ高,能满足后续分子生物学研究的要求。     

云南小粒种咖啡荫蔽栽培研究

云南小粒种咖啡荫蔽栽培有利于咖啡营养生长和生殖生长的平衡,能有效控制主要病虫和草害的发生,有利于咖啡丰产、稳产,提高品质和降低生产成本;咖啡与热带经济作物、果树间作,改善了生态环境,提高了土地利用率和单位土地面积的经济效益:是发展云南小粒种咖啡的最好方式。     

Impacts of weather,shade cover and elevation on coffee leafminer Leucoptera coffeella (Lepidoptera: Lyonetiidae) population dynamics and natural enemies

We assessed the influences of ambient temperature, rainfall, shade cover and elevation on seasonal abundance of coffee leafminer Leucoptera coffeella (Guérin-Ménèville) and its natural enemies in coffee farms in the Soconusco region of Chiapas, Mexico. Mined coffee leaves were most abundant during the rainy season (i.e. historical average rainfall >200 mm/mo, April–November) compared to the dry season (<100 mm/mo, December–March), and at low (<600 m asl) relative to high (>900 m asl) elevations. The abundance of mined leaves increased with rainfall, and decreased with maximum daily temperatures. Coffee leafminer survivorship was highest during the dry season (>40%), when predation was lowest (<10%). Predation was the main source of coffee leafminer mortality, and was greatest during the rainy season (>25%) when coffee leafminer incidence was highest (>30% mined leaves per plant). None of the weather variables that were evaluated (viz. maximum and minimum temperatures, and rainfall) significantly impacted parasitism ratios. Shade cover moderated on-farm temperatures, by reducing maximum daily temperatures and any potential, direct impacts of rainfall on coffee leafminer, by providing partial shelter from rainfall, but did not significantly affect coffee leafminer incidence. In 48 h laboratory trials, coffee leafminer oviposition was highest at 28 °C (∼15 eggs/female), minimal at 25 °C (∼3 eggs) and nil at 20 °C, and higher during night-time hours (>8 eggs/female/day) compared to day-time hours (<1 egg). Historical average temperatures were higher at low elevation (yearly average ca. 25 °C; range = 18.0–32.0 °C) than at high elevation (ca. 21 °C; 13.5–28.5 °C), and we predicted that physical environmental conditions (i.e. night-time hours with temperatures > 20 °C) were permissive of coffee leafminer oviposition during twice as many hours each year at low elevation (4060 h) compared to high elevation (2081 h). Overall, our results suggested that evident differences in the abundance of coffee leafminer between elevations may be due in considerable part to differences in ambient temperatures, particularly night-time temperatures, rather than rainfall, shade cover, or elevation per se.     

Expression and mode of inheritance of resistance in coffee to leaf miner Perileucoptera coffeella

The coffee leaf miner (Perileucoptera coffeella, Guérin-Méneville), is the most serious pest on coffee in Brazil. Coffee varieties with resistance to this pest have been developed in Brazil using genes from the Coffea racemosa Lour. species. Resistance to P. coffeella was studied in C. racemosa and in advanced breeding populations derived from BC3 and BC4 generations through artificial infestation of coffee leaves (laboratory) and natural infestation (greenhouse). Based on an analysis of variance carried out with notes attributed to lesions, two weeks after egg hatching, C. racemosa plants and BC4 progenies were classified in 3 groups according to their degree of resistance to the insect. The age of the leaves seemed to play a role in the expression of resistance of C. racemosa and of BC4 progenies to P. coffeella. The data seemed to show that resistance to P. coffeella derived from C. racemosa can be best explained by two complementary dominant genes. Segregations for resistance assessed in families obtained by selfing or open pollination or by back-crossing with a susceptible variety were similar to the expected segregation of 9 resistant: 7 susceptible or 1 resistant: 3 susceptible, respectively. The symbols Lm1, lm1, Lm2 and lm2 are proposed for the alleles. Consequences for breeding coffee varieties with resistance are discussed.     

施用咖啡果皮对咖啡幼苗生长及土壤理化性状的影响

通过盆栽试验研究施用不同量的咖啡果皮对咖啡幼苗生长及土壤理化性状的影响。结果表明:施用5%(果皮与土壤质量比)以上咖啡果皮的咖啡幼苗地上部、根系干重,总根长,根系直径及根系总体积显著低于对照处理;随咖啡果皮施用量的增加,咖啡幼苗长势显著变差;施用5%以上的咖啡果皮可显著增加土壤碱解氮、速效磷、速效钾养分含量和土壤脲酶、酸性磷酸酶活性,但土壤p H显著下降。综上所述,施用5%以上直接堆沤腐熟的咖啡果皮会抑制咖啡幼苗生长,降低土壤p H,但可显著提高土壤养分含量和土壤脲酶、酸性磷酸酶活性,增加土壤养分有效性。     

咖啡炭疽病菌生物学特性及其毒力测定

根据形态及ITS序列对咖啡炭疽菌进行了鉴定，其次通过菌丝体生长速率法测定了咖啡炭疽病菌的生物学特性及其毒力。生物学特性测定结果表明：菌丝体生长最适合的温度为28～30℃，pH为7～8。赖氨酸和L-甘氨酸有利于菌丝体的生长，光照及碳源对菌落生长影响则不明显。室内毒力测定结果表明：97.5%腈菌唑对咖啡炭疽病菌的抑菌效果最好，其EC50为30.79 μg/mL；其次为95%粉锈宁，其EC50为216.30 μg/mL；接着为97.2%百菌清和98%抑霉唑，其EC50分别为305.61、360.77 μg/mL。     

The homegarden agroforestry system of Bukoba district,North-Western Tanzania. 2. Constrainsts to farm productivity

A questionnaire survey was conducted among 72 randomly selected households in Bukoba district, Tanzania from August to November 1991. The objective of the study was to identify the major constraints to increased productivity in homegardens and farmers response to these constraints. Declining of homegarden productivity seems to have been influenced by the gradual decline of soil fertility mainly as a result of decrease in cattle population, the serious outbreak of banana weevils, nematodes and later Panama disease, fragmentation of homegardens due to population growth and lack of cash. As a result, homegardens can no longer subsist farm families for the most part of the year. The actual decline in banana yield is 66% over the last 20 years. Incomes are too low to support modest investment to improve productivity in homegardens. Farmers' responses to these problems have been out-migration, a shift towards cultivation of root crops, planting of beer banana and decrease in homegarden management intensity. These responses however are likely to offer only short term and partial solutions.     

云南不同海拔小粒种咖啡生长发育情况调查

对云南思茅、保山、德宏、西双版纳4个地区的调查结果，小粒种咖啡在海拔900m以下的植株生长量和第3年的产量大于海拔1 100、1 300m植区的生长量和产量，但随海拔升高咖啡干豆千粒种增加，大象豆减少；随海拔升高，咖啡的果酸度增加，杯品品质提高。     

Selection for bean and liquor qualities within related hybrids of Arabica coffee in multilocal field trials

The success of a new variety of Arabica coffee (Coffea arabica L.) depends to an important extent on its liquor and bean qualities. Selection for these traits is however constrained by the prevalence of large genotype-by-environment (G×E)interactions in conjunction with the low genetic variability characteristic of this species. The aim of this study was to assess the extent to which key bean and liquor traits are affected by the environments and could be combined in order to improve the efficiency of selection for coffee quality in a narrow genetic basis set of hybrids obtained from a set of related lines and collectively representing the Ruiru 11 cultivar. Twenty-one full-sib families representative of this hybrid cultivar grown in Kenya in five sites exhibiting strong edaphic and climatic differences were used for the study. Rainfall amounts during various phases of berry development were used to explain the differences observed in the discriminating abilities of the locations for bean and liquor traits. The results showed that these families were best differentiated for bean sizes in the site where moisture supply was optimal throughout berry expansion and filling stages, whereas discrimination on the basis of liquor traits were best observed in the site where moderate moisture stress occurred during bean filling stage. The overall precision in prediction of family values was low for liquor qualities; but a much more efficient selection for large bold beans, optimally based on the AA grade was shown to be possible. Selection indices for family selection were computed to realize a trade-off between genetic gains in bean size and liquor flavour. This revised version was published online in August 2006 with corrections to the Cover Date.