ABSTRACT.Little is known about the molecular genetic diversity of most Passiflora species. We used RAPD markers to evaluate the genetic diversity of 24 genotypes of the 'sleep' passion fruit (Passiflora setacea). Twelve primers generated 95 markers, 88% of which were polymorphic. The genetic distance estimated by the complement of the Dice index ranged from 0.29 (among accessions Ps-G1 and Ps-G13) to 0.69 (among accessions Ps-G21 and Ps- G23). Genotype grouping based on the UPGMA algorithm showed considerable variability among genotypes. We conclude that P. setacea has a broad genetic base that could be exploited in breeding programs.

ABSTRACT. In spite of the importance of and the considerable variability observed in Passiflora (Passifloraceae), little is known about the genetic diversity of most of the species of this genus. We evaluated the genetic diversity by RAPD markers in 18 genotypes of Passiflora trintae. The 15 primers generated 112 markers, 84% of which were polymorphic. The genetic distance estimated by the complement of the Dice index (average dissimilarity = 0.30) and genotype grouping based on the UPGMA algorithm showed low variability among genotypes. More attention should be given to the study and conservation of the biodiversity of this economically important genus.

ABSTRACT. The genetic diversity and characteristics of commercial interest of Passiflora species make it useful to characterize wild germplasm, because of their potential use for fruit, ornamental and medicinal purposes. We evaluated genetic diversity, using RAPD markers, of 32 genotypes of Passiflora cincinnata collected from the wild in the region of Vitória da Conquista, Bahia, Brazil. Thirteen primers generated 95 polymorphic markers and only one monomorphic marker. The mean genetic distance between the genotypes estimated by the complement of the Dice index was 0.51 (ranging from 0.20-0.85), and genotype grouping based on the UPGMA algorithm showed wide variability among the genotypes. This type of information contributes to identification and conservation of the biodiversity of this species and for the identification of pairs of divergent individuals for maximum exploitation of existing variability.

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In a study of the relationship between leaf apparatus and yield in sunflower, the Rumanian hybrid HS 18 and the French hybrid INRA 4701 were subjected to a variety of leaf removal treatments. These treatments differed both in the number and in the position of the leaves removed. The leaves were removed one at a time during the vegetative period in one series and all at once shortly before flowering in another. The effects of the various treatments on final plant ht., size of head, seed setting and different aspects of yield were determined. INRA 4701 was more sensitive to leaf removal in terms of plant ht. and head size, whereas seed and oil yield were affected more in HS 18. Seed setting in the centre of the inflorescence was better in INRA 4701 than in HS 18 for all treatments. Relative to the untreated controls, however, the effect of leaf removal was more injurious to seed setting in INRA 4701. ADDITIONAL ABSTRACT: A study of the varieties HS18 and INRA4701 showed the leaf efficiency of the former to be twice that of the latter. Defoliation had a greater effect on seed yield and oil yield in HS18 and on for plant height, head diameter, grain weight and seed setting in the central area of the head in INRA4701. (Abstract retrieved from CAB Abstracts by CABI’s permission)