Ornamental use of Capsicum genus chili peppers has expanded due to easy seed propagation, short germination period, diversified fruit colors and harmony of potted plants. The ornamental plant sector requires cultivars adapted to different cultivation conditions in pots and gardens. Breeding programs can use heterosis and combining ability information, aiming to commercially explore hybrids or develop populations for lineage selection with desirable characteristics. However, the ornamental chili pepper field lacks studies with this data. In this study, combining ability of C. annuum accessions was determined for ornamental purposes and hybrid combinations were identified based on heterosis values. Fifteen hybrids were obtained from diallel crosses of six genotypes of C. annuum, from March to September 2014, under greenhouse conditions, grown in five-liter pots in experimental design of randomized blocks with 10 repetitions and one plant per plot. Morpho-agronomic characterization was conducted based on eight quantitative descriptors: plant height (before and after fruiting); canopy diameter; days to flourishing; days to fruiting; fruit length and diameter, and number of fruits per plant. Both additive and dominance effects play important role in controlling the studied characters, indicating hybrid exploitation as well as development of superior lineages from the progress of segregating generations. Negative heterosis values resulted in reduction in height, time for flourishing and fruiting, as well as fruit diameter and length, which are desirable for ornamental Capsicum breeding program. Considering an ideotype for ornamental chili pepper cultivars, the hybrids UENF 1626 x UENF 1750, UENF 1750 x UENF 2030 and UENF 1626 x UENF 2030 can be recommended for cultivation with ornamental purposes.
Loss of biodiversity and ecosystem degradation become major concerns worldwide, making the conservation process an important strategy for maintaining biodiversity. Capsicum chinense Jacq. is the most Brazilian species of the genus, with representatives in different biomes. Anthropic pressure, such as burns, real estate speculation, and changing cultivation habit has led to risks of genetic erosion. Conservation and characterization of conserved accessions are paramount to ensure genetic diversity, useful for the bioeconomy and for genetic improvement. We report the characterization of 55 C. chinense accessions from four different regions of Brazil and one accession from Peru. The accessions were characterized based on 37 morpho-agronomic variables, Inter Simple Sequence Repeats—ISSR and Simple Sequence Repeat—SSR. Qualitative descriptors were analyzed using a descriptive statistical, while the quantitative descriptors were analyzed via F test and significant differences in mean values were separated using Scott-Knott test. The relative contribution of each quantitative trait was determined. A correlation between morphological and molecular distances was calculated. Color of ripe fruit and fruit shape had the largest number of observed classes. Six distinct groups and the joint analysis presented an entanglement rate of 0.58, evidencing the divergence of accessions between the groups of both dendrograms. Bayesian analysis allowed the distinction of two clusters for SSR. A significant variability was observed among accession with potential to integrate several breeding programs.
Capsicum baccatum is one of the most important chili peppers in South America, since this region is considered to be the center of origin and diversity of this species. In Brazil, C. baccatum has been widely explored by family farmers and there are different local names for each fruit phenotype, such as cambuci and dedo-de-moça (lady's finger). Although very popular among farmers and consumers, C. baccatum has been less extensively studied than other Capsicum species. This study describes the phenotypic and genotypic variability in C. baccatum var. pendulum accessions. Twenty-nine accessions from the Universidade Estadual do Norte Fluminense Darcy Ribeiro gene bank, and one commercial genotype ('BRS-Mari') were evaluated for 53 morphoagronomic descriptors (31 qualitative and 22 quantitative traits). In addition, accessions were genotyped using 30 microsatellite primers. Three accessions from the C. annuum complex were included in the molecular characterization. Nine of 31 qualitative descriptors were monomorphic, while all quantitative descriptors were highly significant different between accessions (P < 0.01). Using the unweighted pair group method using arithmetic averages, four groups were obtained based on multicategoric variables and five groups were obtained based on quantitative variables. In the genotyping analysis, 12 polymorphic simple sequence repeat primers amplified in C. baccatum with dissimilarity between accessions ranging from 0.13 to 0.91, permitting the formation of two distinct groups for Bayesian analysis. These results indicate wide variability among the accessions comparing phenotypic and genotypic data and revealed distinct patterns of dissimilarity between matrices, indicating that both steps are valuable for the characterization of C. baccatum var. pendulum accessions.
Resumo -O objetivo deste trabalho foi avaliar alguns aspectos da biologia floral e do sistema reprodutivo de Jatropha curcas, em Janaúba, MG. Foram registrados: o número de flores femininas e masculinas; o intervalo de abertura das flores femininas; e a formação de frutos por apomixia, autofecundação, geitonogamia e xenogamia. A proporção de flores masculinas para femininas foi de 20:1. O intervalo de abertura das flores femininas variou de um a sete dias, conforme o número delas na inflorescência. No teste de apomixia, houve formação de frutos em apenas 5% das flores avaliadas. A percentagem de frutificação variou de 79 a 88% na autofecundação manual, na geitonogamia e na xenogamia. Na autofecundação sem a polinização manual a frutificação foi de 20%, e os frutos formados foram significativamente menores, com número inferior de sementes por fruto e menor índice de velocidade de emergência. As sementes foram semelhantes às formadas por polinização natural. É possível a realização de cruzamentos controlados em pinhão-manso, e não há autoincompatibilidade nesta espécie.Termos para indexação: Jatropha curcas, autofecundação, geitonogamia, polinização natural, xenogamia. Floral biology and artificial polinization in physic nut in the north of Minas Gerais state, BrazilAbstract -The aim of this work was to evaluate some aspects of the floral biology and of the reproductive system of Jatropha curcas, in Janaúba county, MG, Brazil. The number of female and male flowers, the interval between the opening of female flowers, and the formation of fruits by apomixis, self-pollination, geitonogamy and by xenogamy were registered. The ratio of male to female flowers was 20:1. The interval of opening of female flowers was of one to seven days, depending on the number of female flowers in the inflorescence. On the apomixy test, the formation of fruits occurred in only 5% of the evaluated flowers. The fruit set was between 79 and 88% through the manual self-pollination, and through the geitonogamy, and the xenogamy. In the self-pollination treatment, without the hand-pollination, the fruit set was of 20%, and the fruits formed were significantly smaller, with a lesser number of seeds per fruit and lower rate of emergence. The seeds were similar to the ones formed by natural pollination. Artificial cross-pollination is possible on physic nuts, and there is no self-incompatibility within this species.Index terms: Jatropha curcas, self-pollination, geitonogamy, natural pollination, xenogamy. IntroduçãoOs procedimentos adotados na execução dos trabalhos de melhoramento genético de espécies perenes frutíferas arbóreas dependem, fundamentalmente, do seu modo de reprodução, do conhecimento da biologia floral, inclusive a morfologia floral, do tipo de reprodução e dos aspectos relativos à polinização e à fertilização. São importantes, também, as consequências das alterações induzidas artificialmente no modo de reprodução, nos cruzamentos dirigidos e nas autofecundações. Além disso, o fruto e as sementes são economicamente as partes mais ...
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