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1.
Charles O. Agwanda Philippe Lashermes Pierre Trouslot Marie-Christine Combes André Charrier 《Euphytica》1997,97(2):241-248
Resistance to Coffee Berry Disease (CBD) in Arabica coffee is controlled by at least three genes which are present in the
varieties Hibrido de Timor (T gene), Catimor (T gene), Rume Sudan (R and k genes) and K7 (k gene). Hibrido de Timor, Catimor
and Rume Sudan are genetically distant from most of the commercial cultivars, and the utilisation of molecular markers would
greatly improve the efficiency of breeding programmes concerned with CBD resistance. The objectives of the present work were
therefore: (1) to identify random amplified polymorphic DNA (RAPD) markers associated with CBD resistance and (2) to identify
markers which could be used to select against the genetic background of the resistance donors. Identification of RAPD markers
was carried out in three steps. The first step involved the comparison of the RAPD profiles between the susceptible cultivars
and the resistant donors. This was followed by comparison of the RAPD profiles between resistant and susceptible types of
each donor variety. The final step involved assay of the resistance markers in the first and the second backcrosses between
these donors and the recurrent parent. High genetic variability was demonstrated in Catimor, and to some extent in Rume Sudan.
Three RAPD markers were shown to be closely associated to the T gene. Attempts to identify markers associated with the R and
k genes were less rewarding. The implications of the current observations in relation to breeding for CBD resistance in Arabica
coffee are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Juan Carlos Herrera P. Gabriel Alvarado A. Hernando A. Cortina G. Marie-Christine Combes Gladys Romero G. Philippe Lashermes 《Euphytica》2009,167(1):57-67
The objective of this study was to identify polymorphic molecular markers associated with partial resistance to coffee leaf
rust, Hemileia vastarix. A segregating F
2 population derived from a cross between the susceptible Coffea arabica cv. Caturra and a C. canephora-introgressed Arabica line exhibiting high partial resistance was analyzed. Rust resistance measured as rust incidence (RI)
and defoliation (DEF) was evaluated in field conditions in three consecutive years (2003–2005). During the 2003 season, which
was characterized by favorable conditions for a rust epidemic, the F
2 plants exhibited different levels of resistance ranging from very susceptible (50.1% for DEF and 49.5% for RI) to highly
partial resistance (9.1% for DEF and 3.7% for RI). Molecular analysis enabled identification of seven polymorphic markers
(5 AFLP and 2 SSR) exhibiting significant association with partial resistance. Coexistence of resistance homozygous alleles
(RR) at codominant SSR loci was correlated with high resistance. This study is the first attempt to develop PCR-based sequence
specific markers linked to partial rust resistance in coffee. 相似文献
3.
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. 相似文献
4.
Bárbhara Joana dos Reis Fatobene Vinícius Teixeira Andrade Giulia Stefania Aloise Maria Bernadete Silvarolla Wallace Gonçalves Oliveiro Guerreiro Filho 《Euphytica》2017,213(8):196
Arabica coffee production is based on highly productive cultivars; however, these cultivars are susceptible to infestation by several biotic agents, including root-knot nematodes. Collections of wild Coffea arabica germplasm represent an important source of genetic variability for resistant cultivar development. In this study, 1046 plants derived from 71 wild coffee trees were evaluated with respect to Meloidogyne paranaensis resistance. In addition to information on plants reactions, we also evaluated the genetic parameters related to resistance. Progenies from the five most promising plants were also evaluated regarding resistance to M. incognita and M. exigua. The yield potential of selected plants was estimated through analysis of data for fruits harvested in 4 different years. Forty-seven plants were considered resistant based on reproduction factor values. The estimated heritability was high for all analyzed variables leading to substantial selection gain, mainly at the progeny mean level. On the basis of heritabilities and genetic correlations, we conclude that selection could be performed based on values of the gall and egg mass index. However, higher genetic gain could be obtained based on nematode count variables. A second experiment confirmed the reactions of the selected five plants to M. paranaensis, and multiple resistance was detected in three of them. The resistant accessions also have yield potential. 相似文献
5.
Coffee varieties with resistance for the plant-parasitic nematodes Pratylenchus coffeae and Radopholus arabocoffeae are limited in Vietnam. A selection of imported varieties and high yield varieties of Arabica coffee in Vietnam were evaluated
for resistance to both plant-parasitic nematode species in Northern Vietnam. The same experiments were carried out with hybrid
arabica coffee, three selected clones of Coffea
canephora and one clone of Coffea excelsa in the Western Highland of Vietnam. The screened coffee accessions from Ethiopia (KH1, KH13, KH20, KH21, KH29, and KH31)
were susceptible and good host for P. coffeae. Also accessions 90P4 (Portugal) and Oro azteca (Mexico) had a reproduction factor Rf > 1. Pluma Hidalgo (Mexico), 90/6 (Vietnam), 90P3 (Portugal), 90P2 (Vietnam), Variedad (Mexico), 90T (Portugal), and Garnica
(Mexico) were poor hosts (Rf < 1) but not tolerant to P. coffeae, expressed by a reduction of root weight compared to untreated control plants. Most of the coffee accessions tested in Northern
Vietnam were intolerant to R. arabocoffeae, except 90T which showed no reduction of root weight, even at high initial nematode densities (4,000/pot). Good hosts for
R. arabocoffeae were Variedad, KH1, KH21, KH29, KH20, KH31, and KH13 with Rf > 1. Pluma Hidalgo, 90/6, 90P3, 90P2, 90T, Oro azteca, and Garnica were poor hosts (Rf < 1). In the Western Highland experiment, all arabica coffee accessions were susceptible for P. coffeae with Rf ranging from 1.41 to 1.59. Tolerance to P. coffeae was found in C. liberica var. Dewevrei, Hong34 and Nhuantren. Coffea excelsa, Hong34, Nhuantren, and H1C19 were tolerant to R. arabocoffeae at the highest inoculation density (4,000 nematodes/pot). The most susceptible accessions were Nhuantren and K55. Resistance
(Rf < 1) to R. arabocoffeae was found in C. liberica var. Dewevrei and Hong34. This article reports on the first screening for resistance and tolerance to P. coffeae and R. arabocoffeae in coffee accessions in Vietnam and shows promising results for enhanced coffee-breeding. 相似文献
6.
DENG Zhao-jing 《保鲜与加工》2005,(1):153-156
A new definition of inertia,i.e. the momentum is the measuring of inertia of matter, is proposed. The article through and etc., subjects, the correctness of the new notion of inertia:The monentum is the measuring of inertia has been demonstrated, and the unsolved contradictions of the traditional definition of inetia. And the mass is the measuring of inertia has been revealed. 相似文献
7.
灰树花子实体中水溶性多糖提取工艺优化研究 总被引:3,自引:0,他引:3
以水为浸提液,通过单因素试验研究了颗粒度、浸提温度、浸提时间、水料比、醇沉度等因素对灰树花子实体多糖提取率的影响,并采用正交试验对提取工艺进行优化。试验表明,水料比对灰树花子实体多糖提取率的影响最大,其次是浸提时间,浸提温度影响最小。通过对提取条件的优化,结合收益、成本等综合因素选出最佳优化工艺为:浸提温度90℃,浸提时间5 h,水料比25∶1。验证试验显示,在最佳工艺条件下提取的多糖提取率达13.4%。 相似文献
8.
以消化法测定的亚麻籽总磷、无机磷含量为基准,采用正交试验方法对植酸酶反应条件和测无机磷条件进行了研究。试验结果表明,植酸酶的最佳使用条件是:反应液pH值为4.0,反应时间为9 h,加酶量为1:1;测无机磷的条件是:反应液pH值为5.0,反应时间为6 h,温度为60℃。 相似文献
9.
为了研究灰分对煤自燃能力的影响作用,利用绝热氧化实验装置对不同灰分含量煤样进行升温氧化实验,采用R70、TCPT、B 3种指标表征灰分含量对煤样自发氧化过程的影响。结果表明:1)灰分含量越大,煤样低温氧化阶段温升速率越小,温升加速点温度越高,煤样的自发氧化过程越慢,煤越不易自燃;灰分含量大于40%后,煤自燃倾向性快速减弱。温升加速点是反应微观信息的零活化能温度的宏观累计结果,具有直观且滞后的特点。灰分越大,滞后越明显,温差越大。2)R70、TCPT、B 3种指标与灰分关系表现为二次函数。R70和TCPT两种指标显示灰分越大,自燃倾向性越弱,与实践经验相符。受水分权重影响,B指标显示煤样在灰分小于40%时,灰分越大,煤样自燃倾向性越强,这与实践经验相悖。因此,B在判定灰分对煤样自燃倾向性的影响时具有一定的局限性。 相似文献
10.
春小麦蒸发蒸腾的调控 总被引:9,自引:0,他引:9
春小麦蒸发蒸腾受环境条件,土壤水分状况和小麦叶片气孔的综合调控。甘肃河西地区辐射强列,与春小麦蒸发蒸腾具有高度相关性(r〉0.95),决定了该地区作物的高耗水特性。土壤水分条件在水势为-0.01--0.1MPa时,春小麦蒸发蒸腾受气象条件影响和小麦叶片气孔调节的作用较大;当土壤水势降至-0.3--1.5MPa时,叶片气孔开始关闭,太阳辐射对春小麦蒸发蒸腾的作用明显减弱(相关系数r〈0.31)。土壤 相似文献
11.
On the basis of sufficient discussion of hydrogeologic condition of geothermal water in the Xaoquan area, authors a mathematical is studied with MODFLOW model is established, and then the geothermal water is studied with MODFLOW program. Andthe mathematical model is identified. The authors compare the simulative water level with actual water level. The MODFLOW program can study geothermal water,when the simulative water level approximated to actual water level, and the mathematical MODFLOW model is right. Geothermal water under condition of different exploitation is stndied with the MODFLOW program. Sustainable exploitation is achieved. 相似文献
12.
采用浸渍法制备CaO/MgO固体碱催化剂,并应用于菜籽油与甲醇的酯交换反应制备生物柴油。考察了镁钙比对CaO/MgO催化活性的影响。试验表明,用质量分数22.6%的乙酸钙浸渍MgO,镁钙摩尔比为3~4时最接近等体积浸渍,镁钙摩尔比为1~2时为过量浸渍。镁钙摩尔比越低,催化剂活性越高,但镁钙摩尔比低于3时,催化剂活性组分分布不均匀,且活性增加不明显。所以最佳镁钙摩尔比为3~4。 相似文献
13.
The structure of liquid mercury is determined by 0 -20 type powder diffractometer. A new simple method is proposed to analy the structure of non-atom liquid by using the intensity diffraction profiles. It is found that the space between two nearest neighbor Hg atoms is 3.00 A and the second near neighbor atoms is 3.38 A. The method of peak separation for X-ray diffraction profile is proved to be effective by applying to non-atom liquid system. 相似文献
14.
15.
Automobile comfort dynamic simulation is necessary when we predict and evaluate the comfort of a automobile or optimize performance of automobile. The nine DOF vibration model of automobile is established , which acts root mean square value of body in multiple work conditions as comfort evaluation indices. Based on the comfort simulation, the Hongyan 1160 is predicted in the way of comfort. The programmes can be used in many different automobiles . The computational result indicates that the model can simulate vibration of automobile truly. It is significant to research automobile comfort evaluation to optimize performance of automobile and comfort simulation .The computational program can be applied to optimize or simulate which has some reference value. 相似文献
16.
Carburization is a complex manufacturing process with serious disturbance and time delay,which is multi-variable and uncertain.It is difficult to set up an exact mathematic model.Moreover,by means of conventional control methods and experience,satisfying control result can't be obtained.In this paper,according to the characteristic of controlled-object,Fuzzy control method has been chosen to design a Fuzzy-PI controller and a mixed-PID Fuzzy controller.The result of simulation shows that the robust performance and control result of the new Fuzzy controllers is better than the conventional PID controller.The overshoot is smaller.It is helpful to improve the quality of carburizing workpieces. 相似文献
17.
The amount of limestone powder, which is a by product of manufactured fine aggregate, is larger and larger with the increase of manufactured fine aggregate. Environment will be severely polluted if the powder is improperly used. The effects of limestone powder on workability, compressive strength, and impermeability of concrete were studied when cement is substituted for the mass proportion of 0, 10, 15, 20 percent with it. The results show that the performances of concrete are better improved when the percentage of limestone powder is about 10 percent. The wet packing density of mixture of limestone powder and cement was measured, and it shows that the degree of density was biggest when limestone powder is 10 percent. This shows that the best mixing proportion of limestone powder and cement may be determined through measuring the change of compactness of mixture of limestone powder and cement. 相似文献
18.
高粱──苏丹草杂交种的选育和利用 总被引:9,自引:1,他引:9
利用高粱、苏丹草强大的杂种优势,选育的高粱──苏丹草杂交种经试验、示范,不仅单株优势明显、单位面积产量高,而且品质也十分优良,用于养鱼和养牛,均获得成功。 相似文献
19.
棉花种子介电特性的试验研究 总被引:2,自引:1,他引:2
将棉花种子简化为一种复合介质模型,通过试验测试种子的介电常数,探讨种子的介电特性,分析频率、湿度与种子介电特性的关系,得出介电常数随各参数变化的规律,为合理地确定介电式种子分选机的结构参数和工况参数提供理论依据。对外表完整与表面破裂的种子进行吸湿性的对比试验研究,从而为提高介电式种子分选机的分选效果创造条件。 相似文献
20.
梨园生草对果树部分害虫天敌的影响 总被引:1,自引:0,他引:1
摘要:【研究目的】为研究梨园生草对果树害虫天敌的影响,【方法】采用3种生草方式和托盘法调查方法。【结果】结果表明,种植三叶草、苕子和自然生草,对保护害虫天敌都具有良好的效果,8次调查天敌数量之和,种植三叶草、苕子和自然生草依次为387头、300和149头;土壤清耕,不利于保护害虫天敌。梨园生草也为害虫提供了栖息场所,其中以自然生草的数量最大为3267头,以后依次为种植三叶草、苕子和土壤清耕处理,分别为2622、2026、122头。结果还显示天敌和害虫之间存在相似的消长规律。【结论】与梨园土壤清耕相比,果园生草有利于保护果园生物多样性,对保护害虫天敌作用明显,其中以种植三叶草效果最好。 相似文献