排序方式: 共有37条查询结果,搜索用时 31 毫秒
31.
Aurélie Lécolier Pascale Besse André Charrier Thierry-Nicolas Tchakaloff Michel Noirot 《Euphytica》2009,168(1):1-10
Coffee is one of the main products on the international markets, in association with oil, corn, sugar, and paper pulp. The
history of coffee-tree cultivation is incompletely documented, both regarding its domestication in Africa, and its assisted
dispersal throughout the world. This review focuses on the coffee mutant, Coffea arabica ‘Laurina’ (Chevalier A in Encyclopedie Biologique. Vol 28, 1947), also named ‘Bourbon pointu’. This plant is generally acknowledged
to have been selected in the island of ‘Bourbon’ (La Réunion) from a field at the beginning of the 19th century. Compared
with the common ‘Bourbon’ variety, ‘Bourbon pointu’ trees are dwarf, with a characteristic Christmas-tree shape and the beans
have an excellent cup quality. Although cited many times in literature, the origin of this variety is ambiguous and is largely
discussed even today with increasing confusion, particularly in books and local newsletters. This article provides a thorough
historical and bibliographical review of coffee cultivation in La Réunion, which leads to an understanding of the bottleneck
responsible for the low genetic diversity of the ‘Bourbon’-type modern varieties. Complemented by a review of the scientific
studies conducted on this subject, confirmation of the veracity of the various historical accounts becomes possible, and appropriate
conclusions on the origin of the ‘Bourbon pointu’ are derived. Although historical texts provide important information and
represent priceless resources that give direction to scientific research, it is clear that this same research makes it possible,
in turn, to clarify and to interpret historical texts.
相似文献
Michel NoirotEmail: |
32.
Thibaud Surini Fatima Charrier Jér?me Malvestio Bertrand Charrier Amine Moubarik Patrick Castéra Stéphane Grelier 《Wood Science and Technology》2012,46(1-3):487-501
An original heat treatment performed under vacuum pressure was investigated. Maritime pine samples were treated at six different temperatures: 140, 160, 180, 200, 230 and 260°C. The physical and mechanical consequences, i.e. bending strength (MOR), modulus of elasticity (MOE), hygroscopic behaviour, equilibrium moisture contents and anti-swelling efficiency (ASE) were studied. A no-choice feeding test according to the NF EN 117 standard was achieved. Temperatures up to 200°C had no significant effect on wood properties. However, at 230 and 260°C, the decrease in MOR was severe, reaching 42.5 and 62.5%, respectively. Whatever the treatment conditions, wood samples were still highly degraded by termites, revealing no increase in their durability. 相似文献
33.
34.
35.
Summary
Theobroma cacao pollen fertilization capability was studied after 0, 50, 100, 200, 500 and 1000 Gy gamma-irradiation. For all irradiation doses, no alteration of pollen grain viability and in vitro germination was observed. In situ, for all doses, pollen tubes penetrated into the styles and reached the ovules 20 hours after pollination. In vitro observations of the pollen grain nuclei after 20 hours incubation showed that pollen irradiation causes inhibition of the division of the generative nucleus. Fruit survival rate 30 days after pollination decreased as irradiation doses increased from 0 to 100 Gy, and over 100 Gy no fruit set was obtained. The possibility of using irradiated pollen as a method for obtaining haploid cacao plantlets is discussed. 相似文献
36.
Summary Doubled haploids (DH) of Coffea canephora Pierre were developed using haploid embryos which occur spontaneously in association with polyembryony. The frequencies of polyembryonic seeds and haploid embryos varied according to the parental genotypes. However, production of a large number of DH seemed possible from all genotypes. More than 750 DHs produced from various genotypes were grown under field conditions and evaluated for different characters of agronomic importance. Approximately half of DH genotypes did not survive, suggesting a strong, negative effect of homozygosity. Inbreeding depression is particularly severe on general vigor and reproductive aspects. For several characters studied such as leaf shape, leaf rust resistance and hundred bean weight, considerable genetic variations were observed within and between groups of DHs constituted by the DHs produced from the same clone. Despite their low vigor and reduced fertility, the DHs of C. canephora offer new possibilities in genetic research and coffee breeding. 相似文献
37.
Summary Two breeding populations have been identified with Coffea canephora, based on geographical and genetic differences: the Guinean group from West Africa and the Congolese group from central Africa. A reciprocal recurrent selection programme based on these groups was initiated in Côte d'Ivoire in 1984. Genotypes of both groups available in field collections are either of cultivated or wild origin.Genotypic and phenotypic variability was evaluated within and between the groups for the following characteristics: isozyme patterns, architecture, drought tolerance and vigour, technological and organoleptic traits, pest and disease resistance. Variation between and within groups was found to be large. Based on isozyme analysis and phenotypic observations, two subgroups were identified within the Congolese group. Phenotypic values of parents and testers used in the first cycle of reciprocal recurrent selection are presented.Results of two intergroup hybrid trials indicate high yield and vigour for these hybrids compared to intragroup hybrids, justifying the reciprocal selection approach. Furthermore, the variation observed indicates that recurrent selection would allow progress for selection traits for both populations and intergroup hybrids. 相似文献