Evaluation of the in vitro regeneration capacity in Brazilian industrial tomato

Este trabalho teve por objetivo avaliar a capacidade de regeneração das cultivares detomateiro industrial (Lycopersicon esculentum Mill) IPA-5 e IPA-6, utilizando quatro composições demeio de cultura descritos na literatura e cinco variações de inoculação. Foi testada uma nova variação deinoculação, denominada cotilédone fendido. A maior freqüência de formação de gemas vegetativas foi100% no caso de IPA-5, e 65% no caso de IPA-6. Para induzir o alongamento de brotos, foramnecessários três subcultivos dos explantes apresentando gemas. No caso de IPA-5, o número de brotosobtidos foi maior quando a indução de gemas foi realizada em meio contendo BAP (2,5 mg L-1) eAIA (0,2 mg L-1) seguido de três subcultivos, em meio como zeatina (0,5 mg L-1). Usando esse protocolo,a cultivar IPA-5 produziu uma média de 5,45 brotos alongados a partir do cotilédone fendido. Essacapacidade excedeu significativamente o cotilédone aparado, que produziu 4,4 brotos alongados porexplante. No caso de IPA-6, a melhor combinação de meios e método de inoculação produziu0,87 broto alongado por explante. Os brotos alongados foram enraizados e transferidos para casa devegetação.The objective of this work was to evaluate the regeneration capacity of the IPA-5 andIPA-6 Brazilian industrial tomato (Lycopersicon esculentum Mill) cultivars using four compositions ofculture media described in the literature and five inoculation methods. A new variation of inoculation,the split cotyledon method, was also tested. The largest frequency of shoot bud formation was 100%in the case of IPA-5 and 65% in the case of IPA-6. To induce shoot elongation, it was necessary toaccomplish three subcultures of the explants presenting shoot buds. In the case of IPA-5, the numberof the obtained shoots was higher when the induction of shoot buds was accomplished in culturemedium containing BAP (2.5 mg L-1) and IAA (0.2 mg L-1) followed by three subcultures on zeatin(0.5 mg -1) containing medium. Using such protocol, the IPA-5 cultivar produced, on the average, 5.45elongated shoots through the split cotyledon method. That capacity exceeded significantly the trimmedcotyledon method, which produced 4.4 elongated shoots per explant. In the case of IPA-6, the bestcombination of culture medium and inoculation method produced 0.87 elongated shoot per explant.The elongated shoots were rooted and transferred to greenhouse

Maternal environment on seed germination and viability in cowpea / Ambiente materno na germinação e viabilidade de sementes de feijão-caupi

 Seed quality is determined by the environmental conditions to which they were exposed during their formation. Thus, the objective of this study was to evaluate the seed viability and seedling formation of cowpea cultivars produced in a high-temperature environment. Seeds of the cowpea cultivars Carijó, Itaim and Tapahium produced in growth chambers under temperature regimes T°1: 20-26-33 °C and T°2: 24.8-30.8-37.8 °C were used. The experimental design was completely randomized, with four replicates of 25 seeds, placed to germinate at a temperature of 25 °C in B.O.D chambers. Increase in air temperature during seed production did not hamper germination percentage. However, the 4.8 °C increase in air temperature reduced the vigor of seeds of the cultivar Tapahium, resulting in an increase in the number of abnormal seedlings. Seeds of the cultivars Carijó and Itaim produced under temperature regime 24.8-30.8-37.8 °C showed higher performance

Effects of paclobutrazol concentrations and periods of immersion on garlic crop

O presente trabalho foi conduzido no período de abril a setembro de 1989 no Campo Experimental do Setor de Olericultura da UFLA, Lavras, MG, com o objetivo de avaliar a influência de concentrações e períodos de imersão em paclobutrazol sobre o controle do pseudoperfilhamento e características comerciais do alho (Allium sativum L.). Utilizou-se o delineamento experimental de blocos ao acaso em esquema fatorial 4 x 5, compreendendo quatro doses de paclobutrazol (0, 500, 1.000 e 1.500 mg L-1 de i.a.) e cinco períodos de imersão (30, 60, 90, 120 e 150 minutos) e quatro repetições. Observou-se, com o incremento das concentrações de paclobutrazol, uma redução na altura e no número de folhas por planta aos 60 e 90 dias após o plantio. A concentração de 976 mg L-1 de paclobutrazol proporcionou o maior peso médio de bulbo, e a dose de 451 mg L-1 foi a que promoveu a maior porcentagem de bulbos graúdos. Quanto a produtividade total e comercial, porcentagem de bulbos pseudoperfilhados e número de bulbilhos por bulbo, não se verificaram diferenças significativas entre os tratamentos.This study was carried out from April to September of 1989, in the experimental field of UFLA, Lavras, MG, Brazil, with the objective of evaluating the influence of concentrations and periods of immersion of paclobutrazol on secondary growth control and marketable traits in garlic (Allium sativum L.). The experimental design was a randomized complete block in a 4 x 5 factorial scheme, with four replications. The first factor consisted of paclobutrazol concentrations (0, 500, 1,000 and 1,500 mg L-1 of a.i.), and the second one of periods of immersion (30, 60, 90, 120 and 150 minutes). Reduction in plant height and in number of leaves per plant from 60 to 90 days after planting with paclobutrazol applications was observed. Mean bulb weight increased up to the concentration of 976 mg L-1 of paclobutrazol, and 451 mg L-1 gave the greatest percentage of bulbs of large size. There was no significant difference among treatments for total and commercial yields, percentage of secondary growth bulbs and number of cloves per bulb

Initial growth of cowpea cultivars with an increase of 4.8 ° C in air temperature / Crescimento inicial de cultivares de feijão-caupi com aumento de 4,8 ° C na temperatura do ar

Vigorous germination and uniform seedling establishment are determinant and dependent on the performance of cultivars in the face of rising air temperatures. Thus, the objective was to evaluate the initial development of different cultivars of cowpea against the increase of 4.8 ° C in the daily temperature regime. The experiment was carried out in growth chambers, in a 5x2 factorial scheme (cultivars x temperature regimes). It was evaluated: germination percentage, germination speed index, average germination time, average germination speed, average germination speed, the initial seedling length and the initial seedling dry weight. The increase of 4.8 ° C in the temperature did not affect the germination percentage of the seeds, being above 90%. The germination speed index and the average germination speed were higher at temperatures of 24.8-30.8-37.8 ° C. For the germination percentage, the cultivars Pujante, Rouxinol and Tapahium presented the highest indexes, above 90%. The germination speed index and the average germination speed were higher for cv. For Rouxinol, consequently, the average germination time was shorter. The initial seedling length did not differ between cultivars, with an average value of 17.73 cm. The cv. Pujante differed among the other cultivars in terms of seedling dry mass. The initial growth and dry mass of seedlings were higher in the environment with a temperature of 24.8-30.8-37.8 ° C The 4.8 ° C increase in air temperature does not affect the initial phase of cowpea. The germinative parameters of this legume vary according to the cultivars

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

Comparative cytogenetic analysis of two grasshopper species of the tribe Abracrini (Ommatolampinae, Acrididae)

The grasshopper species Orthoscapheus rufipes and Eujivarus fusiformis were analyzed using several cytogenetic techniques. The karyotype of O. rufipes, described here for the first time, had a diploid number of 2n = 23, whereas E. fusiformis had a karyotype with 2n = 21. The two species showed the same mechanism of sex determination (XO type) but differed in chromosome morphology. Pericentromeric blocks of constitutive heterochromatin (CH) were detected in the chromosome complement of both species. CMA3/DA/DAPI staining revealed CMA3-positive blocks in CH regions in four autosomal bivalents of O. rufipes and in two of E. fusiformis. The location of active NORs differed between the two species, occurring in bivalents M6 and S9 of O. rufipes and M6 and M7 of E. fusiformsi. The rDNA sites revealed by FISH coincided with the number and position of the active NORs detected by AgNO3 staining. The variability in chromosomal markers accounted for the karyotype differentiation observed in the tribe Abracrini