Sebastião Márcio de Azevedo

Zingiberene-mediated resistance to the South American tomato pinworm derived from Lycopersicon hirsutum var. hirsutum

The Lycopersicon hirsutum var. hirsutum accession PI 127826 is recognized as a good source of resistance to arthropod pests due to the action of the allelochemical zimgiberene, a sesquiterpene present in its glandular trichomes. Five genotypes were selected from the F2 generation of the interspecific cross Lycopersicon esculentum ‘TOM-556’ × Lycopersicon hirsutum var. hirsutum ‘PI 127826’, based on their low levels (BPX-368-clone#56) or high levels(BPX-368-clone#92, BPX-368-clone#105,BPX-368-clone#179, BPX-368-clone#250) of zingiberene. The five F2 genotypes were tested for resistance to the South American tomato pinworm Tuta absolutaalong with accession L. esculentum ‘TOM-556’ (pinworm susceptible), and the accessions L. hirsutum var. hirsutum ‘PI 127826’ and L. pennellii ‘LA716’ (resistant). The F2 clones selected for high foliar zingiberene levels showed lower scores for leaflet lesion type(LLT), percent leaflets attacked (PLA) and overall plant damage (OPD) than the low zingiberene genotypes. The results indicated that zingiberene mediates resistance to the South American pinworm, based on feeding and on ovipositing deterrence, in populations derived from the interspecific cross between Lycopersicon. esculentum and Lycopersicon hirsutum var. hirsutum. Indirect selection for high foliar zingiberene content is suggested as an efficient technique for breeding tomatoes for resistance to the South American tomato pinworm.

Resistance to papaya ringspot virus in summer squash Cucurbita pepo L. introgressed from an interspecific C. pepo × C. moschata cross

Early infections of the papaya ringspotvirus-watermelon strain (PRSV-W) in summersquash Cucurbita pepo may causemarketable yield losses of up to 100%. Because control of the viral disease viamanagement of vector insects is notefficient, incorporation of PRSV-W geneticresistance into C. pepo cultivarswould be highly desirable. Althoughresistant accessions have been described inC. ecuadorensis, C.foetidissima, C. maxima and C.moschata, resistant accessions of C.pepo are rare. This paper reports oninterspecific hybridization between C.pepo and a PRSV-W-resistant C.moschata squash accession, and on theearly steps in introgression of thisresistance into the former species. C. pepo cv. Asmara was crossed with twoPRSV-W resistant C. moschataaccessions. Immature F1 (C.pepo× C.moschata) embryos were excised20 days after pollination, and culturedasseptically in two different culturemedia, each under two different lightregimes. No adult plants could berecovered from immature embryos of thecross C. pepo cv. Asmara × C.moschata cv. Piramoita. From the crossC. pepo cv. Asmara × C.moschata cv. Duda, 4 seedlings wererecovered from 6 embryos incubated in agrowth chamber [25° to 28 °C,16 hours of light with 1500–2000 lux/ 8 hdark period] immediately after excision andinoculation in a culture medium [=Murashige and Skoog (MS) + 0.01 mg/L of IAA(indolacetic acid) + 0.1 mg/L of Kinetin],without an intervening dark period. F1 (C. pepo × C. moschata)plants were fertile, and upon selfingyielded viable F2 seeds. PRSV-Wresistance was assessed in the F2 (C. pepo × C. moschata) population,using C. pepo cv. Asmara and C.moschata cv. Duda, respectively, as thesusceptible and resistant (tolerant)checks. Plants were mechanically inoculatedwith a known PRSV-W isolate. The F2population showed a PRSV-W responseintermediate between those of the parentalaccessions, and estimates of the meandegree of dominance indicates incompletedominance in the direction ofsusceptibility. The mean broad-senseheritability estimate of PRSV-W resistancewas 0.48, a medium to high value,indicating the likelihood of a significantresponse to selection for resistance. Theintrogression of the resistance to PRSV-Wof C. moschata into C. peposeems to be technically viable.

Resistance to the South American tomato pinworm in tomato plants with high foliar acylsugar contents

A traca-do-tomateiro foi constatada pela primeira vez no Brasil em 1980 estando hoje dentre as principais pragas da tomaticultura nacional. O controle desta praga e feito principalmente por inseticidas, sendo realizada em casos extremos, ate tres pulverizacoes semanais. Acessos silvestres de tomateiro como S. pennellii LA-716 possuem resistencia a pragas, mediada pela presenca de acilacucares nos foliolos. Os objetivos deste trabalho foram obter genotipos de tomateiro com caracteristicas comerciais e altos teores foliares de acilacucares (AA), e avaliar seus niveis de resistencia a traca do tomateiro Tuta absoluta. Os genotipos foram obtidos a partir de populacoes segregantes (F2) oriundas do cruzamento entre AF-8665 (linhagem elite com baixos teores de AA) e as linhagens BPX370E-30-275-11-7, BPX370E-30-275-11-8, BPX370E-30-380-68-6 e BPX370E-30-380-68-8 (linhagens pre-comerciais com altos teores, obtidas a partir do cruzamento interespecifico S. lycopersicum x S. pennellii LA-716). Plantas F2 previamente selecionadas com base nos teores de AA foram clonadas e em seguida testadas quanto a resistencia a traca-do-tomateiro. Genotipos selecionados para altos teores de AA expressaram menor ovoposicao da traca e niveis inferiores de danos causados a planta pela infestacao do microlepidoptero do que genotipos (comerciais ou nao) com baixos teores de AA. Embora genotipos com altos teores de AA tenham sido mais resistentes a traca do que os demais, seus niveis de resistencia podem ser dependentes do background genotipico: clones BPX-410H (alto teor de AA) mostraram-se em geral ligeiramente mais resistentes do que o dos clones BPX-370G (tambem alto teor de AA). Os clones BPX-410H-01pl#281, BPX-410H-04pl#348 e BPX-410H-04pl#481 foram superiores nas avaliacoes de resistencia a traca e sao recomendados para a continuidade do programa de melhoramento.

Compostos secundários em cachaças produzidas no estado de Minas Gerais

The Brazilian sugar-cane spirit chemical compounds classified like secondary compounds are one group of Brazilian sugar-cane spirit minor compounds formed during the fermentation process. That compounds are important for the taste and flavor of spirits in general, mainly esters and aldehydes. However, that compounds are above the standard quality established by Agriculture Ministry (MAPA), they can affect the Brazilian sugar-cane spirit quality and be harmful to the health. Aiming to evaluate the sugar-cane spirit secondary compounds from diverse sites at Minas Gerais State, 45 samples were randomized sampled and taken to the Brazilian Sugar-Cane Spirit Analysis Laboratory of UFLA during the period of August of 2000 to July of 2001. The results showed that there were high and significant statistical difference between the samples analyzed regarding higher alcohol, esters, aldehydes and volatile organic acids. Among 45 Brazilian sugar-cane spirits analyzed, 7 showed excess of higher alcohol, 2 showed excess of aldehydes and 3 showed excess of organic acids, therefore 24,4% of Brazilian sugar-cane spirits analyzed were out of the standard quality established by MAPA (1997).

Levantamento da contaminação por cobre nas aguardentes de cana-de-açúcar produzidas em Minas Gerais

A cachaca artesanal e, geralmente, produzida em destiladores de cobre, os quais conferem melhor qualidade ao produto, se comparados aos alambiques confeccionados com outros materiais, como aco inox, podendo contaminar o produto quando o manejo da producao e inadequado. A contaminacao de aguardentes ocorre em consequencia do acumulo do azinhavre nas paredes dos destiladores, o qual e solubilizado na aguardente. O excesso de cobre soluvel no organismo humano (hipercupremia) pode ser toxico devido a afinidade do cobre com grupos S-H de muitas proteinas e enzimas, causando doencas como epilepsia, melanomas, artrite reumatoide e doencas psiquiatricas. Assim, com o presente trabalho objetivou-se avaliar o teor de cobre em diferentes aguardentes e orientar os produtores sobre possiveis contaminacoes e suas influencias na saude humana. Para tal, 45 amostras de cachaca, provenientes de diferentes municipios de Minas Gerais, foram analisadas quanto ao teor de cobre no Laboratorio de Analise Fisico-Quimica de Aguardente do Departamento de Quimica da Universidade Federal de Lavras (DQI/UFLA). A determinacao ou quantificacao do cobre presente nas aguardentes foi realizada por meio de medidas espectrofotometricas na regiao visivel do espectro, em comprimento de onda de 546 nm. Foram constatadas contaminacoes excessivas de cobre em 6,7% das amostras, que se encontravam acima do limite permitido pelo decreto do Ministerio da Agricultura, Pecuaria e do Abastecimento (MAPA). Verificou-se que alguns alambiques apresentavam ma higienizacao em alguns setores, o que pode ter contribuido para a elevacao nos teores de cobre, como tambem de outros produtos toxicos ao homem.

Alcobaça ALLELE AND GENOTYPIC BACKGROUNDS AFFECT YIELD AND FRUIT SHELF LIFE OF TOMATO HYBRIDS

Post-harvest shelf life of tomato fruit may be increased by deploying mutant alleles which affect the natural ripening process and/or by a favorable genotypic background. Among the several ripening mutant genes, alcobaca (alc) has proved to be highly efficient in increasing shelf life of commercial tomato fruits, especially in heterozygosis, a state at which no limiting deleterious effects upon fruit color occur. The effects of heterozygosity in the alcobaca locus (alc+/alc) on yield and fruit quality traits of tomato hybrids with three genotypic backgrounds. We evaluated three pairs of hybrids obtained from crosses between the near-isogenic pollen source lines Flora-Dade (alc+/alc+) and TOM-559 (alc/alc), and three maternal lines (Stevens, NC-8276 and Piedmont). The six treatments were factorial combinations of two different status in the alc locus (alc+/alc and alc+/alc+) versus three different genotypic backgrounds (maternal lines). Fruits were harvested at the breaker stage of maturation and stored in shelves at 21oC for 14 days. Yield and fruit quality traits were then evaluated. Regardless of the background, the alc allele in heterozygosis (alc+/alc) did not interfere with the total yield, commercial yield, average mass per fruit, average mass per commercial fruit, fruit shape, or with fruit peduncular scar diameter. The alc+/alc genotype reduced the rate of firmness loss and delayed evolution of the red color of the fruit, thus contributing to an increase of the post-harvest shelf life for all three genotypic backgrounds.

Adaptabilidade e estabilidade produtiva de genótipos de tomateiro em condições de temperatura elevada

The objective of this work was to evaluate the adaptability and stability of 15 tomato genotypes in the area of Gurupi, Tocantins. The experiments were carried out in two environments [greenhouse: in the summer (December to March) and in open field: winter (June to September)], with 15 experimental tomato genotypes, being: four of the type long shelf life commercial ripening mutants and pre-commercial (rin): Tyler, Rebeca, Carmem and AF 13527; nine of the type long shelf life structural commercials and pre-commercial: Lumi, Debora Max, Michelli, Tammy, AF 12525, AF 11097, AF 13363, AF 13364 and AF 13525; and two of normal fruits: Santa Clara and Drica, in randomized block design with three repetitions. The long life genotypes e Tyler, Rebeca, AF 13364, AF 13525, AF 13527 it were classified as of stability and wide adaptability and wide adaptability for yield. For the average weight of commercial fruits, the genotypes Tyler, Michelli and AF 11097 presented wide adaptability to the evaluated environments.

Obtenção de anticorpos policlonais contra proteínas presentes em plantas afetadas pela anomalia declínio dos citros

O declinio dos citros, uma anomalia de etiologia desconhecida, continua sendo um dos entraves para o setor citricola, uma vez que nao existem medidas de prevencao e controle para as plantas acometidas pela anomalia. Para a caracterizacao e estudo da anomalia, muita enfase tem sido dada a mudanca na expressao genica de plantas afetadas, que culmina no acumulo de proteinas. Proteinas totais extraidas dos vasos do xilema de raizes de plantas afetadas pela anomalia, quando separadas por eletroforese no sistema SDS-PAGE 12,5%, apresentam um perfil eletroforetico contendo proteinas com massas moleculares de cerca de 21, 23, 31 e 42 kDa, sendo que plantas consideradas sadias apresentam proteinas de 21, 31 e 42 kDa. Com este trabalho objetivou-se obter anticorpos contra essas proteinas, bem como a titulacao adequada para os mesmos. Duas inoculacoes subcutâneas foram realizadas em coelhos, espacadas de 15 dias, ambas usando cerca de 120 µg de proteina isolada, sendo que cada coelho recebeu uma proteina especifica, visando a producao de anticorpos. A primeira sangria foi realizada aos 21 dias apos a primeira inoculacao e as demais semanalmente. A tecnica Western Blotting foi realizada para a confirmacao da especificidade dos anticorpos, bem como para determinacao das respectivas titulacoes. O titulo 1:1500 foi aquele que proporcionou maior especificidade para as proteinas de 21, 23 e 31 kDa. Para a proteina de 42 kDa a melhor titulacao foi de 1:3000. Estes anticorpos poderao ser utilizados em estudos para caracterizacao dessas proteinas.

POSTHARVEST CONSERVATION OF STRUCTURAL LONG SHELF LIFE TOMATO FRUITS AND WITH THE MUTANT RIN PRODUCED, IN EDAPHOCLIMATIC CONDITIONS OF THE SOUTHERN STATE OF TOCANTINS

The high temperature of growth environment can affect the postharvest quality of tomato fruits. In this situation, an alternative for the farmers is the use of hybrid cultivars that produce long shelf life fruit with longer postharvest shelf life when compared to normal varieties of fruits. The objective of this research was to compare the postharvest conservation of fruits of structural long shelf life tomato hybrids and with the mutant rin. The fruits evaluated were from fifteen tomato genotypes produced under the edaphoclimatic conditions of the southern State of Tocantins, being four of them long shelf life type hybrids (with rin allele) which were: Tyler, Rebeca, Carmem and AF 13527; nine of them structural long shelf life hybrids: Lumi, Debora Max, Michelli, Tammy, AF 12525, AF 11097, AF 13363, AF 13364 and AF 13525; and two normal fruit cultivars: Santa Clara and Drica. The fruits were harvested at the breaker stage and stored in a controlled environment (20 °C and relative humidity of 60%). The half-life firmness of fruits of genotypes with a structural genotypic long shelf life background ranged from 6.25 to 13.44 days for the genotypes Tammy and AF13525, respectively, not differing from the long shelf life genotypes with rin allele. Despite the fact that daytime temperatures are higher than those recommended for the tomatoes crops, it was observed that if the fruits are stored in appropriate conditions (20 °C and relative humidity of 60%), the color and firmness of the fruits with a long shelf life genotypes with rin allele and structural genotypic background evolve more slowly than the fruits of normal genotypes. Under these conditions, it took the fruits 7 to 8 days to acquire a red color on more than 80% of the surface after being harvested.