Melon (Cucumis melo L.) crops are grown in the Semiarid region of Brazil by small, medium, and large farmers, focused on domestic and international markets. However, melon is also grown by family farmers using their own seeds, which are important germplasm for melon breeding programs. Samples of these seeds were collected and stored in the Active Germplasm Bank of Cucurbitaceae from the Northeast Region at the Brazilian Agricultural Research Corporation (Embrapa Semiarid), and require more thorough studies for a better understanding of the existing variability. Thus, the objective of this work was to characterize sub-accessions and their respective endogamic progenies to assess the genetic variability between and among these accessions. Two experiments were conducted in a randomized complete block design, with three replications, using 11 quantitative and 8 qualitative descriptors: the first using seeds from 17 accessions from natural pollination, and the second using seeds from S1 progenies. Morphological data were used for comparisons between generations. The 17 accessions evaluated originated 24 sub-accessions, denoting variability between and among accessions and sub-accessions. A dendrogram developed based on the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) showed the existing variability and, according to the newest melon classification, the groups identified were: makuwa, subgroup nashi-uri; and momordica and cantalupensis, subgroup prescott. The results showed a probable existence of introgression of alleles between different botanical groups, and some sub-accessions were not identified regarding their group by presenting variations in morphological characteristics, indicating the presence of new botanical groups.
Family farming in Brazil holds a high diversity of melon germplasm, composing an important source of alleles for breeding programs. Thus, the objective of this study was to estimate genetic parameters and select genotypes from a population of melon sub-accessions from different botanical varieties grown by family farmers, based on morphological parameters. Two experiments were conducted, one in 2019 and another in 2020, in a complete randomized block design, with three replications and five plants per plot, using 27 melon sub-accessions (generation S2) from family farmers, and a commercial variety. Nine quantitative descriptors were evaluated. Assumptions of ANOVA were tested, followed by individual and joint analyses of variance. Significant differences were found among sub-accessions for all descriptors evaluated, with heritabilities higher than 83% and significant genotype-environment interactions for 88.8% of the characteristics evaluated. Thus, genetic variability was found among sub-accessions, with predominance of genetic effects over environmental effects, denoting the possibility to obtain genetic gains by the improvement of several characteristics of agronomic interest. The sub-accessions BGMEL66.0, BGMEL111.0, and BGMEL112.0 are recommended for inclusion in breeding programs focused on obtaining good prolificacy and small fruits with high soluble solid contents. BGMEL sub-accessions (108.3 and 108.5) can generate progenies with high prolificacy, and sub-accessions of the variety momordica can be used for generation of progenies focused on shortening the crop cycle and increasing fruit size.
Lippia origanoides Kunth. is a medicinal plant that is widely available in the Northeast region of Brazil and is known as “alecrim-d’angola”. However, there is no information available on the genetic variability of this species in the region. Thus, the current study was aimed to analyze the genetic diversity and structuring of L. origanoides populations occurring in the states of Bahia and Pernambuco, Brazil, using Inter-Simple Sequence Repeat (ISSR) molecular markers. The evaluated Nei’s diversity index of the populations varied from 0.162 to 0.237, and the Shannon diversity index varied from 0.247 to 0.350. In molecular variance (AMOVA) analysis, a variation of 31% was observed among the populations, which denotes a high interpopulation structuring. The structure analysis and dendrogram indicated the possibility of classifying the 18 populations into four groups. As their genetic structure is extremely high, it is important to collect L. origanoides germplasm, including as many populations as possible. Since the region of Chapada Diamantina holds the most diverse populations of L. origanoides germplasm, it is a priority area to obtain the germplasm.
Croton (Euphorbiaceae) includes more than 1,300 accepted species and new species of the genus are continuously being described, which are mainly from Brazil. Two new species, Croton aemulus and C. graomogolensis, are herein described, placed in C. sect. Barhamia subsect. Barhamia, and compared to C. muscicapa and C. longibracteatus. The new species are supported by their geographic distributions, ecology, and anatomical and morphological features. Both species are only known from the state of Minas Gerais, Brazil. Croton aemulus occurs in cerrado de altitude (mountain savannah) and C. graomogolensis occurs in campo rupestre (rupestrian grasslands) vegetation.
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