Efeito de substratos e recipientes na aclimatização de goiabeiras Paluma multiplicadas in vitro.

O objetivo desse trabalho foi determinar oefeito de diferentes tipos de substratos e recipientes na aclimatização de goiabeira Paluma multiplicadas in vitro

Efficiency of natural insecticides and thiamethoxam on the control of thrips in grapes and selectivity to natural enemies.

The objective of this work was to verify the efficiency of natural insecticides and thiamethoxan on the control of Selenothrips rubrocinctus and Frankliniella sp. and their selectivity to natural enemies

Organogênese in vitro de videira.

O objetivo do presente trabalho foi avaliar o efeito da N6-benzilaminopurina (BAP) no processo de regeneração via organogênese in vitro,em sete cultivares de videira

Micropropagação e aclimatização de goiabeira Paluma.

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Eficiência de inseticidas naturais e tiametoxam no controle de tripes em videira e seletividade para inimigos naturais.

O objetivo deste trabalho foi avaliar a eficiência de produtos naturais e do tiametoxam no controle de tripes em videira e seus efeitos sobre inimigos naturais. O experimento foi instalado em plantio comercial, no município de Juazeiro-BA (Brasil), em parreiral da variedade Benitaka, com 5 anos de idade, irrigado por microaspersão. Adotou-se o delineamento experimental em blocos ao acaso, com 4 repetições e 5 tratamentos, sendo: 1. Nim-I-Go a 0,5%; 2. Rotenat a 0,5%; 3. Bio Alho a 0,3%; 4. tiametoxam 250WG (20 g de produto comercial/100L) e 5. testemunha (sem inseticida). Foram utilizadas 12 plantas por tratamento, sendo avaliados o número de tripes e de inimigos naturais por inflorescência, em pré-aplicação e aos 2, 4 e 6 dias após a aplicação dos inseticidas. Os produtos naturais Rotenat e Nim-I-Go apresentaram as melhores porcentagens médias de controle (respectivamente, 52,04% e 48,37%), seguidos pelo tiametoxam (46,00%) e pelo Bio alho (23,07%). Aos dois dias após a aplicação, o tiametoxam apresentou eficiência de 76,79%, porém não manteve a eficiência ao longo das avaliações. As notas na escala de seletividade para o Bio Alho, Nim-I-Go, Rotenat e tiametoxam foram 2 (pouco tóxico), 3 (moderadamente tóxico), 3 e 4 (tóxico), respectivamente

Can anthocyanin presence ameliorate the photosynthetic performance of Prunus saplings subjected to polyethylene glycol-simulated water stress?

The aim was the evaluation of the biochemical and physiological responses of green- (GP) and red-leafed (RP) Prunus cerasifera mature leaves to 20 d of polyethylene glycol (PEG 6000)-induced water stress in order to elucidate a possible ameliorative role exerted by anthocyanins. At 10 d, the anthocyanin content remained unchanged in RP water-stressed leaves. Photosynthetic rate was lower in GP than that of RP (83.4 vs. 76.5%, respectively), paralleled by a higher degree of photoinhibition (Fv/Fm) in GP leaves. Leaves of GP accounted for higher content of soluble sugars at 10 d, when RP only showed a slight sucrose increase. At 20 d of stress, both morphs recovered their Fv/Fm values, suggesting the ability of both genotypes to adjust their photosynthetic metabolism under conditions of water stress. In conclusion, besides the sunscreen role served by anthocyanins, the carbon sink by these flavonoids might have further prevented sugar accumulation and the consequent sugar-promoted feedback regulation of photosynthesis in drought-stressed red leaves

Photosynthetic traits and biochemical responses in strawberry (Fragaria × ananassa duch.) leaves supplemented with led lights

Selected light wavebands promote plant development and/or the biosynthesis of targeted metabolites. This work offers new insights on the effects of red (R), green (G), blue (B), and white (W – R:G:B; 1:1:1) LED light supplementation on physiochemical traits of strawberry leaves. Gas exchange and chlorophyll fluorescence parameters, photosynthetic pigments, and superoxide anion (•O2–) content were analysed in plants grown for 1 (T1) and 17 (T17) d with light supplementations. At T1, light supplementations resulted in the enhancement of the de-epoxidation state of xanthophylls and nonphotochemical quenching, but no changes were observed in maximal photosynthetic rate (PNmax), irrespective of light spectra. At T17, xanthophyll contents remained higher only in R-supplemented plants. Overall, W light resulted in higher photosynthesis, whilst R and B light depressed PNmax values and promoted•O2 – formation at T17. G light did not induce variations in photosynthetic traits nor induced oxidative stress at both T1 and T17

Supplemental red LED light promotes plant productivity, “photomodulate” fruit quality and increases Botrytis cinerea tolerance in strawberry

This work provides new evidences on the effect of pre-harvest red (R), green (G), blue (B), and white (W - R:G:B; 1:1:1) LED light supplementation on production, nutraceutical quality and Botrytis cinerea control of harvested strawberry fruit. Yield, fruit color, firmness, soluble solid content, titratable acidity, primary and specialized metabolites, expression of targeted genes and mold development were analyzed in fruit from light-supplemented plants, starting from the strawberry flowering, radiating 250 mu mol m-2 s-1 of light for five hours per day (from 11:00 to 16:00 h), until the fruit harvest. Briefly, R light induced the highest productivity and targeted antho-cyanin accumulation, whilst B and G lights increased the accumulation of primary and secondary metabolites especially belonging to ellagitannin and proanthocyanidin classes. R light also promoted pathogen tolerance in fruit by the upregulation of genes involved in cell wall development (F x aPE41), inhibition of fungus poly-galacturonases (F x aPGIP1) and the degradation of B. cinerea beta-glucans (F x aBG2-1). Our dataset highlights the possibility to use red LED light to increase fruit yield, "photomodulate" strawberry fruit quality and increase B. cinerea tolerance. These results can be useful in terms of future reduction of agrochemical inputs through the use of R light, enhancing, at the same time, fruit production and quality. Finally, further analyses might clarify the effect of pre-harvest supplemental G light on postharvest fruit quality

Creedy, Jean Iris

The final stage of leaf ontogenesis is represented by senescence, a highly regulated process driven by a sequential cellular breakdown involving, as the first step, chloroplast dismantling with consequent reduction of photosynthetic efficiency. Different processes, such as pigment accumulation, could protect the vulnerable photosynthetic apparatus of senescent leaves. Although several studies have produced transcriptomic data on foliar senescence, just few works have attempted to explain differences in red and green leaves throughout ontogenesis. In this work, a transcriptomic approach was used on green and red leaves of Prunus cerasifera to unveil molecular differences from leaf maturity to senescence. Our analysis revealed a higher gene regulation in red leaves compared to green ones, during leaf transition. Most of the observed DEGs were shared and involved in transcription factor activities, senescing processes and cell wall remodelling. Significant differences were detected in cellular functions: genes related to photosystem I and II were highly down-regulated in the green genotype, whereas transcripts involved in flavonoid biosynthesis, such as UDP glucose-flavonoid-3-O-glucosyltransferase (UFGT) were exclusively up-regulated in red leaves. In addition, cellular functions involved in stress response (glutathione-S-transferase, Pathogen-Related) and sugar metabolism, such as three threalose-6-phosphate synthases, were activated in senescent red leaves. In conclusion, data suggests that P. cerasifera red genotypes can regulate a set of genes and molecular mechanisms that cope with senescence, promoting more advantages during leaf ontogenesis than compared to the green ones