Luciana Nogueira Londe

Divergência genética entre genótipos de alface por meiode marcadores AFLP

Considering the restricted diversity of species available to counteract vitamin deficiencies in Brazil, Kerr and coworkers have been engaged since 1981, in developing genetic improved garden vegetables rich in vitamin A. One of these vegetables is the lettuce cultivar Uberlândia 10,000, which contains 10,200 UI of vitamin A per 100 grams of fresh leaves. This study compares the genetic diversity between Uberlândia 10,000 and its parental, evaluating selection efficiency through the AFLP technique. The following lettuce genotypes were used for this comparison: Maioba, Salad Bowl-Mimosa, Moreninha-de-Uberlândia, Vitoria de Santo Antao, smooth 8th and 9th generation Uberlândia 10,000, and crinkly 8th and 9th generation Uberlândia 10,000 cultivars. The AFLP technique was effective for identifying very close genotypes and for studying lettuce progenies. The primer PR15 enabled the separation of smooth and crinkly types down to 1.8% of genetic diversity and the 8th and 9th generations down to only 0.71% of diversity. Phylogenetic study of the cultivar confirmed the success of the breeding program, with the Uberlândia 10,000 cultivar revealing high vitamin A content and 92% of similarity with the parental Vitoria de Santo Antao. The primer PR11 allowed the identification of polymorphism between cultivars with high and low resistance to septoriosis, suggesting that these bands may be resistance-related.

Characterization of DNA polymorphisms in Caryocar brasiliense (Camb.) in populations with and without thorn at the endocarp by RAPD markers

Caryocar brasiliense (pequi), is one of the main species at the biome of the Brazilian savannah due to its use in culinary, popular medicine, industry in general, and iron and steel industry. At São José do Xingu (MT), a tree of C. brasiliense without thorn at the endocarp was found, which enables the improvement of C. brasiliense not only for consumption but also to the high appreciation it already has. To detect the existing differences between the pequi with and without the thorn at the endocarp, RADP markers were used. The generated polymorphisms were cloned and sequenced in order to identify the sequences that are responsible for the fenotypical alteration. It was observed that the pequi without thorn is genetically isolated from the other populations of pequi with thorn at the endocarp, proving that this characteristic is related to the genetic divergence of the species. Analysis in BLASTn evidenced the similarity of the Dof1 genes of Zea mays to its gene of phosphinotricin acetyl transferase. In the analysis of BLASTx, the similarity was verified to the proteins responsible for the deficiency in ferric reductase 4, and catalase.

Induction of different types of callus in Jatropha curcas L. hybrid accession at in vitro condition

Micropropagation protocols depend on several factors, particularly on the types, combinations, and levels of plant growth regulators used in the culture media. The aim of this study was to determine the influence of 6-Benzylaminopurine (BAP) and Naphtalen-3-acetic acid (NAA) concentrations on callus induction of Jatropha curcas L. explants. The plant material used was a jatropha hybrid accession developed through intraspecific crosses between Costa Rica and Mexico genetic resources (TREC 49 x TREC 33 accession codes). Callus cultures were initiated from hypocotyl explants isolated from 15-days-old seedlings, on Murashige and Skoog (MS) basal medium supplemented with 0; 2 or 4 mg L-1 BAP and 0; 1 or 2 mg L-1 NAA in different combinations. Better-quality callus formation was obtained in medium supplemented with BAP 2 mg L-1 and NAA 1 mg L-1. This combination of plant growth regulators resulted in higher amount of white colored and friable calli, which are more likely to differentiate in bud shoots and roots, depending upon the plant growth regulations added to the media. Our results suggest that BAP (2 mg L-1) and NAA (1 mg L-1) combined can be used for in vitro callogenesis of J. curcas hybrid accession and that it can be adapted to a large-scale in vitro mass production system or to support biotechnological protocols.

Cryopreservation of banana’s cv Grand Naine in vitro rhizomes

The preservation of banana genetic material is usually performed through seedlings. However, most banana cultivars do not produce seed and are propagated vegetatively. Therefore, cryopreservation is a feasible technique that allows the preservation of banana genotypes indefinitely. For the success of cryopreservation protocols, the selection of cryoprotectants and pre-freezing techniques are important factor. Therefore, the objective of this study was to verify the effects of different cryoprotectants with and without 1% phloroglucinol and pre-cooling periods on the development of a protocol for cryopreservation of in vitro rhizomes ofMusa accuminata(AAA) cv Grand Naine banana. The addition of 1% phloroglucinol to the cryoprotective solutions, such as PVS2 enhanced recovery of cryopreserved banana rhizomes. In addition, pre-cooling of explants in ice for 3 hours in PVS2 + 1% of phloroglucinol allowed efficient cryopreservation of banana rhizomes, followed by successful recovery and regeneration of in vitro shoots of banana cv Grand Naine.

Cultivo in vitro da bananeira Prata Anã clone Gorutuba, em meio líquido, agitado e estacionário

The aim of this study was to evaluate in vitro cultivation of banana Prata Ana clone Gorutuba in differents volumes of liquid medium in the stationary system and under agitation, comparing with the traditional cultivation in semisolid medium. The experiment was conducted in a completely randomized design with factorial 5 x 2 + 1, with five volumes (10, 15, 20, 25 and 30 mL) of liquid medium and two cropping systems (agitation and stationary) and control (semisolid medium), with 4 replicates, each plot had a bottle with 4 explants. The number of shoots/explant observed by the control on the third subculture differs from some treatments in liquid medium. In the fourth subculture, the number of shoots/explant of the control differed from all treatments in liquid medium, and cultivation under agitation system favored a number of shoots/explant significantly higher than that obtained by the stationary system. In the elongation and rooting phases, the results obtained in liquid medium, they were better than the control. Comparing the two systems of cultivation in liquid medium, we noted greater growth for plantlets which remained under agitation with the volume of 30ml. The cultivation in semisolid medium is more efficient in vitro multiplication phase, and in the phase of elongation and rooting the best system to be adopted is the cultivation in liquid medium under agitation to 30 mL.

Genetic structure from the oldest Jatropha germplasm bank of Brazil and contribution for the genetic improvement

Jatropha is a potential oilseed crop, which requires mitigating factors such as the low genetic variability of the species. The solution runs through the research of Brazilian germplasm. Attention should be given to the germplasm of jatropha the north of Minas Gerais, because this is the oldest national collection and because this region may be a regions of jatropha diversity due to selection pressure arising from environmental adversities. Therefore, the objective of this study was to investigate the genetic diversity of 48 accessions of collection from Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG), using SSR and ISSR markers. The results showed low genetic diversity, but some individuals stood out as J. mollissima (48), J. podagrica (47), Mexican accessions (42, 43, 44 and 45) and some national accessions (28, 29, 41 and 46). Therefore, aiming to increase the genetic variability and improve the effectiveness of jatropha breeding programs, it is suggested to explore such as parental accessions to generate commercial hybrids. This fact implies the possibility to support future production of jatropha, since this culture may be an important source of income, especially for small farmers living in semiarid regions of Brazil.