No abstract

Sex expression and floral morphology studies are central to understand breeding behavior and to define the productive potential of plant genotypes. In particular, the new bioenergy crop Jatropha curcas L. has been classified as a monoecious species. Nonetheless, there is no information about its reproductive diversity in the Mesoamerican region, which is considered its center of origin and diversification. Thus, we determined sex expression and floral morphology in J. curcas populations from southern Mexico and Guatemala. Our results showed that most of J. curcas specimens had typical inflorescences with separate sexes (monoecious); meanwhile, the rest were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most important variables to group these populations, based on a discriminant analysis, were: male flower diameter, female petal length and male nectary length. From southern Mexico “Guerrero” was the most diverse population, and “Centro” had the highest variability among the populations from Chiapas. A cluster analysis showed that the accessions from southern Mexico were grouped without showing any correlation with the geographical origin, while those accessions with atypical sexuality were grouped together. To answer the question of how informative are floral morphological traits compared to molecular markers, we perform a Mantel correlation test between the distance matrix generated in this study and the genetic distance matrix (AFLP) previously reported for the same accessions. We found significant correlation between data at the level of accessions. Our results contribute to design genetic improvement programs by using sexually and morphologically contrasting plants from the center of origin.

This study addresses the in vitro culture as an alternative to obtain compounds with cytotoxic activity from the medicinal plant Jatropha curcas (Euphorbiaceae). We determined the presence of cytotoxic compounds in both whole plants and dedifferentiated cells. We evaluated the effect of auxin, cytokinins and light on callus induction in cotyledon explants. We found that the most effective combination to induce callus was the auxin 2,4-D (5 mM) with the cytokinin 6-BAP (2.5 mM), on Murashige-Skoog medium in darkness. We compared the callogenic potential among accessions from different geographic origins, finding that ARR-251107-MFG7 is most prone to form callus. The roots of J. curcas grown in field produced a compound chromatographically similar to the cytotoxic diterpene jatrophone. The profile of compounds extracted from the dedifferentiated cells was similar to that of the whole plant, including a relatively abundant stilbene-like compound. This study contributes to the future establishment of protocols to produce anti-cancer compounds from J. curcas cultivated in vitro.

Sex expression and floral morphology studies are central to understand breeding behavior and to define the productive potential of plant genotypes. In particular, the new bioenergy crop Jatropha curcas L. has been classified as a monoecious species. Nonetheless, there is no information about its reproductive diversity in the Mesoamerican region, which is considered its center of origin and diversification. Thus, we determined sex expression and floral morphology in J. curcas populations from southern Mexico and Guatemala. Our results showed that most of J. curcas specimens had typical inflorescences separate sexes (monoecious), meanwhile the rest were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most important variables to group these populations, based on a discriminant analysis, were: male flower diameter, female petal length and male nectary length. From the southern Mexico "Guerrero" was the most diverse population and in Chiapas "Centro". On the other hand, a cluster analysis showed that the accessions from southern Mexico were grouped without showing any correlation with the geographical origin, while those accessions with atypical sexuality were grouped together. Additionally, a Mantel test showed a significant correlation between the distance matrix generated in this study and the genetic distance matrix (AFLP) previously reported for the same accessions. Our results contribute to design genetic improvement programs by using sexually and morphologically contrasting plants from the center of origin. 24 Sex expression and floral morphology studies are central to understand breeding behavior and to 25 define the productive potential of plant genotypes. In particular, the new bioenergy crop 26 Jatropha curcas L. has been classified as a monoecious species. Nonetheless, there is no 27 information about its reproductive diversity in the Mesoamerican region, which is considered its 28 center of origin and diversification. Thus, we determined sex expression and floral morphology 29 in J. curcas populations from southern Mexico and Guatemala. Our results showed that most of 30 J. curcas specimens had typical inflorescences separate sexes (monoecious), meanwhile the rest 31 were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most 32 important variables to group these populations, based on a discriminant analysis, were: male 33 flower diameter, female petal length and male nectary length. From the southern Mexico 34 "Guerrero" was the most diverse population and in Chiapas "Centro". On the other hand, a 35 cluster analysis showed that the accessions from southern Mexico were grouped without showing 36 any correlation with the geographical origin, while those accessions with atypical sexuality were 37 grouped together. Additionally, a Mantel test showed a significant correlation between the 38 distance matrix generated in this study and the genetic distance matrix (AFLP) previously 39 reported for the same accessions. Our results contribute to des...

Sex expression and floral morphology studies are central to understand breeding behavior and to define the productive potential of plant genotypes. In particular, the new bioenergy crop Jatropha curcas L. has been classified as a monoecious species. Nonetheless, there is no information about its reproductive diversity in the Mesoamerican region, which is considered its center of origin and diversification. Thus, we determined sex expression and floral morphology in J. curcas populations from southern Mexico and Guatemala. Our results showed that most of J. curcas specimens had typical inflorescences separate sexes (monoecious), meanwhile the rest were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most important variables to group these populations, based on a discriminant analysis, were: male flower diameter, female petal length and male nectary length. From the southern Mexico "Guerrero" was the most diverse population and in Chiapas "Centro". On the other hand, a cluster analysis showed that the accessions from southern Mexico were grouped without showing any correlation with the geographical origin, while those accessions with atypical sexuality were grouped together. Additionally, a Mantel test showed a significant correlation between the distance matrix generated in this study and the genetic distance matrix (AFLP) previously reported for the same accessions. Our results contribute to design genetic improvement programs by using sexually and morphologically contrasting plants from the center of origin.