Search

Summary Meloidogyne enterolobii (Me) is an emerging root-knot nematode (RKN) and the most important worldwide for its high aggressiveness and increasing geographical distribution. In Mexico only in watermelon and tomato has been reported. Here we report the presence of this nematode in Jalapeño pepper collected in the state of Sinaloa. The morphological and morphometric characteristics of the second-stage juveniles and adult females were similar to those described for Me. DNA sequencing and alignment analysis (BLAST/GenBank) showed that the SCAR and rDNA IGS2 fragments had a 99 % of identity, with Me DNA sequences present in the database. The results obtained indicate that the RKN detected corresponds to M. enterolobii. To our knowledge, this is the first report of this nematode in chilli pepper in this region of Mexico, considered of major economic importance for the variety of vegetables grown and the extension of the area sown.

Made available in DSpace on 2019-10-06T15:54:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Root-knot nematode Meloidogyne mayaguensis Rammah & Hirschmann is a limiting factor in guava tree (Psidium guajava L.) production around the world. An alternative to address this problem is the use of resistant root-knot nematode rootstocks. However, the guava nursery system which is based on herbaceous stem cutting propagation needs to be modified as a rootstock produced via cutting must be grafted with nematode susceptible commercial cultivars. Thus, the objective of this study was to verify the feasibility of omega bench grafting in guava tree propagated by herbaceous stem cutting. Root-knot nematode tolerant ‘Tailandesa’ herbaceous stem cuttings was used as rootstock and ‘Paluma’ and ‘Pedro Sato’ as commercial cultivar grafts. It was observed 100% rooting, cutting survival, and leaf retention on rootstocks grafted with ‘Paluma’ and ‘Pedro Sato’. However, grafting take was not successful as the tissues presented fast oxidation, dehydration and graft death in both commercial cultivars. However, the immersion of the grafts into a solution containing 2.0% citric acid and 1.0% ascorbic acid controlled the oxidation process and resulted in 28.6% and 37.5% successful grafting in the combinations ‘Paluma’/‘Tailandesa’ and ‘Pedro Sato’/’Tailandesa’, respectively. Faculdade de Ciências Agrárias e Veterinárias (FCAV) Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias (FCAV) Universidade Estadual Paulista (UNESP)

The in vitro paralysis of second-stage juveniles of Meloidogyne incognita, M. javanica and M. mayaguensis by aqueous extracts of 15 West African Crotalaria species was analysed. A multivariate analysis distinguished four groups, based on their nematostatic activity: i) C. glaucoides extracts were not active; ii) the root extracts from C. goreensis, C. lathyroides and C. perrottetii were more active than the shoot extracts; iii) the shoot extracts from C. comosa and C. cylindrocarpa were more active than the root extracts; iv) both shoot and root extracts of C. atrorubens, C. barkae, C. grantiana, C. hyssopifolia, C. pallida, C. podocarpa, C. retusa, C. senegalensis and C. sphaerocarpa have nematostatic effects depending on either the Crotalaria species or plant tissue from which the extracts were derived. However, considering the greater biomass contribution of the leaves and stems compared to the roots when the plants are used as green manure, C. barkae, C. grantiana, C. pallida and C. podocarpa are the most efficient Crotalaria species, whatever the Meloidogyne species targeted.