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Bien que consid r e comme culture mineure ou culture << orpheline >> le voandzou peut contribuer efficacement r soudre d'importantes probl matiques mondiales telles que la faim, la pauvret et l'adaptation aux changements climatiques. Il est une source prometteuse de prot ines v g tales et a l'avantage d'avoir de nombreux morphotypes largement cultiv s par les populations rurales. Malheureusement pendant le stockage cette ressource est en proie une pression des ravageurs qui engendrent des pertes quantitatives et qualitatives. L'objectif de cette tude, est de d terminer en condition contr l e, le degr de vuln rabilit de 40 morphotypes cod CM/R gion/Collection/no(01 40) vis- -vis de Callosobruchus maculatus. Au cours de trois campagnes de collecte des donn es et interviews men es dans le Cameroun septentrional, des informations sur la diversit de graines de voandzou ont t collect es, puis ramen es en laboratoire. L' valuation de la sensibilit vari tale de cette collection, a repos sur l'analyse des param tres qui d finissent l' chelle de sensibilit savoir: le nombre d'oeufs pondus, le nombre d'oeuf et de larves morts, le nombre d'individus merg s et l'indice de susceptibilit . Il ressort que le nombre d'oeufs pondus par C. maculatus est compris entre 56,5[+ or -]19,65 (CM/EN/DW/01) et 111,5[+ or -]58,69 CM/EN/MC/34. Le taux d' mergence varie entre 58,23% (CM/EN/EA/02) et 96, 70% (CM/EN/DW/24). L'analyse statistique des valeurs li es l'indice de susceptibilit montre une diff rence tr s hautement significative (p < 0,0001). Il existe une forte corr lation n gative entre l' mergence et la mortalit larvaire (r = -0,97). La classification ascendante hi rarchis e a permis de r aliser un dendrogramme regroupant les morphotypes en 7 classes distinctes en fonction du degr de susceptibilit . La classe I montre de fa on sp cifique trois morphotypes les plus r sistants aux attaques de la bruche (CM/EN/DW/09, CM/EN/AE/02 et CM/EN/MC/49) dans cette exp rimentation. Les vari t s qui ont pr sent une r sistance la bruche peuvent tre adopt es ou exploit es pour le d veloppement des vari t s plus int ressantes pour les producteurs, les consommateurs et les transformateurs. D'autre part, compte tenu des changements globaux qui affectent l'agriculture en g n rale et certaines esp ces mineures dites n glig es et sous-utilis es en particulier, il serait imp ratif de trouver des strat gies de conservation efficaces court, moyen et long terme pour r pondre la demande alimentaire de plus en plus importante au Cameroun. Mots cl s: voandzou, indice de susceptibilit , r sistance, valuation, bruche, attaque, mergence lavaire, Cameroun Although considered a minor crop or 'orphan' crop, Bambara groundnut can effectively contribute to solving important global problems such as hunger, poverty and adaptation to climate change. It is a promising source of plant protein and has the advantage and has the advantage of having numerous morphotypes to be widely cultived by rural populations. Unfortunately during storage this resource is subject to pest pressure which leads to quantitative and qualitative losses. The objective of this study is to determine, under controlled conditions, the degree of vulnerability of 40 morphotypes code CM/Region Collection/ no(01 to 40) collected with regard to C. maculatus. During three campaigns of data collection and interviews conducted in northern Cameroon, information on the diversity of voandzou seeds was collected, seeds were collected in the field during three campaigns in the three northern regions of Cameroon, then brought back to the laboratory. The assessment of varietal sensitivity for this collection, is based on an analysis of the parameters that define the sensitivity scale, namely: the number of eggs laid, the number of dead eggs and larvas, the number of emerged individuals and the susceptibility index.The number of eggs laid by C. maculatus ranged from 56.5[+ or -]19.65 (CM/EN/DW/01) to 111.5[+ or -]58.69 CM/EN/MC/34. Emergence rates ranged from 58.23% (CM/EN/EA/02) to 96.70% (CM/EN/DW/24). Analysis of susceptibility index values shows a highly significant difference (p < 0.0001). There is a strong negative correlation between emergence and larval mortality (r = -0.97). Cluster analysis was used to produce a dendrogram grouping morphotypes into 7 distinct classes according to degree of susceptibility. Class I specifically shows three of the most resistant morphotypes to bruchid attacks (CM/EN/DW/09, CM/EN/AE/02 and CM/EN/MC/49) in this experiment. Varieties that have shown a resistance to bruchid beetle may be adopted or exploited for the development of more interesting varieties for growers, consumers and processors. On the other hand, given the global changes affecting agriculture in general and certain neglected and under-utilised minor species in particular, it would be imperative to find effective short-, medium- and long-term conservation strategies to meet the growing demand for food in Cameroon Key words: Bambara groundnut, susceptibility index, resistance, evaluation, weevil, attack larval emergence, Cameroun, INTRODUCTION Les estimations r centes de l' tat de la s curit alimentaire et de la nutrition dans le monde, parues en juillet 2022, font tat de ce que le [...]

Controlled inoculations with 10 bulk inocula of Cronartium quercuum (Berk) Miyabe ex Shirai f.sp. fusiforme were carried out on open-pollinated progeny of 25 fast-growing Pinus taeda L. parents. The parents had a range of breeding values for resistance to fusiform rust in progeny field trials. There were highly significant differences among the halfsib families in response to inoculations, and these differences were very reproducible; the half-sib family-mean heritability of resistance to controlled inoculation was 0.97. All of the families that were susceptible in the field were susceptible in controlled inoculations, and most (12 of 17) of the field-resistant families were resistant in response to controlled inoculations. Significant pathogenic variability was observed among the different bulk inocula, although this accounted for only 1.9% of the total variation. Genetic differences among families within field-resistant or field-susceptible groups accounted for 13.7% of the total variation. The family by inocula interaction was highly significant, but a single field-resistant family contributed 44% of the total family by inocula interaction variance, and two other field-resistant families also showed significant interactions. Des tests d'inoculation controlee avec 10 sources d'inoculum de Cronartium quercuum (Berk) Miyabe ex Shirai f. sp. fusiforme ont ete effectues sur des descendances issues de pollinisation libre et provenant de 25 parents de Pinus taeda L. a croissance rapide. Les parents representaient une gamme de valeurs genetiques pour la resistance a la rouille fusiforme dans des tests de descendance sur le terrain. Il y avait des differences significatives parmi les descendances uniparentales en reaction aux inoculations et ces differences etaient tres reproductibles; l'heritabilite moyenne des descendances uniparentales pour la resistance aux inoculations controlees etait de 0,97. Toutes les familles qui etaient sensibles sur le terrain etaient egalement sensibles dans les essais d'inoculation controlee et la plupart (12 sur 17) de celles qui etaient resistantes sur le terrain etaient egalement resistantes dans les essais d'inoculation controlee. Une variation significative de la pathogenicite a ete observee parmi les sources d'inoculum bien que cela ne representait que 1,9 % de la variation totale. Les differences genetiques entre les familles parmi les groupes de familles resistantes ou sensibles sur le terrain representaient 13,6 % de la variation totale. L'interaction famille x source d'inoculum etait tres significative mais une famille contribuait a elle seule 44 % de la variation de l'interaction famille x source d'inoculum qui etait egalement significative chez deux autres familles resistantes sur le terrain. [Traduit par la Redaction], Introduction Fusiform rust disease, caused by Cronartium quercuum (Berk) Miyabe ex Shirai f.sp. fusiforme (Cqf), is manifested by swollen regions called galls on stems or branches of pines, and is [...]

Abstract: Plant O-methyltransferases (OMTs) constitute a large family of enzymes that methylate the oxygen atom of a variety of secondary metabolites including phenylpropanoids, flavonoids, and alkaloids. O-Methylation plays a key [...]

In recent years, agricultural scientists have begun to explore novel strategies for isolating plant compounds of potential medicinal value. One such strategy involves exploiting the defense mechanisms of the plant [...]