Published online by Cambridge University Press: 23 January 2009
Introduction. Tejocote (Crataegus spp.) is an edible fruit species that some Mesoamerican cultures have cultivated since pre-Hispanic times in Mexico; however, this fruit crop has not undergone formal breeding. It is unknown whether morphological markers associated with fruit size exist to be used for indirect selection; this could be important, because this species has a large cycle. Our research aimed at studying phenotypic correlations between leaf and stomata characters with fruit weight; such correlations might be used as morphological markers for selection of superior germplasm for fruit weight. Materials and methods. Pearson’s correlation coefficients of 36 leaf variables and three leaf stomata variables with fruit weight were calculated in 94 genotypes of four different species. Results. As expected, the correlations calculated for each species and for the species pool differed. However, the number of veins in leaves of reproductive shoots was positively correlated with fruit weight (P ≤ 0.05) in the two most important horticultural species. On the other hand, C. mexicana was the best option for selecting superior germplasm, and the most significant variables correlated with fruit weight in this species were leaf major axis length of large vegetative shoots, leaf elongation ratio and number of veins of reproductive shoot leaves. Discussion. These variables could be good selection indices or morphological markers that can be used for early screening of germplasm for yield potential.