1-Methylcyclopropene and Aminoethoxyvinylglycine effects on yield components of field-grown cotton

Abstract

Biotic and abiotic stresses can alter the hormone balance and trigger the activation of pathways involved in the cotton stress responses, resulting in the abscission of squares, flowers and young bolls and consequent reductions in the seed cotton yield and fiber yield. As part of the mechanism that primarily regulates the protective response of plants against stresses, ethylene is considered a key hormone involved in this response, and increased ethylene synthesis has been observed when plants are subjected to stress. Thus, the development of strategies aimed to mitigate their negative effects can reduce the shed rate of reproductive structures and positively impact cotton productivity. For this purpose, 1-methylcyclopropene (1-MCP), a compound that inhibits the action of ethylene, and aminoethoxyvinylglycine (AVG), an ethylene synthesis inhibitor, were sprayed on cotton plants to investigate their effects on the seed cotton yield (SCY), fiber yield (FY), fiber percentage (% Fiber) and final stand of plants (STAND) during two cotton growth seasons (2010 and 2011). To this end, experiments were performed in a randomized complete block design with five replicates. Our results demonstrate that the inhibitors of ethylene synthesis and action increased the seed cotton and fiber yield during both growing seasons. The results obtained after AVG spraying in the initial reproductive phase (first square emission) presented the highest values for the cotton yield components and are the first record of the success of this method in Brazil.Index terms: AVG, 1-MCP, ethylene, Gossypium hirsutum. RESUMOA ocorrência de estresses bióticos e abióticos pode alterar o balanço hormonal e desencadear a ativação de vias envolvidas nas respostas do algodoeiro a estresses, resultando na abscisão de botões, flores e maçãs em desenvolvimento e em menor rendimento de algodão em caroço e de fibras. Como parte desses mecanismos que primariamente regulam as respostas protetivas da planta contra estresses, o etileno é considerado um hormônio chave, envolvido nessas respostas e aumentos em seu nível de síntese têm sido verificados em plantas submetidas a quaisquer tipos de estresse. Assim, o desenvolvimento de estratégias objetivando mitigar os seus efeitos negativos poderia reduzir a taxa de queda de estruturas reprodutivas e impactar positivamente na produtividade de fibras. Com esse propósito, 1-methylcyclopropeno (1-MCP), um composto inibidor da ação do etileno e aminoethoxyvinylglycina (AVG), um inibidor da sua síntese foram aplicados sobre o algodoeiro para investigar seus efeitos sobre o rendimento de algodão em caroço, de fibras, a percentagem de fibras e o stand final de plantas durante duas estações de crescimento (2010 e 2011). Assim, experimentos a campo em delineamento blocos casualizados completo com cinco repetições foram conduzidos. Os resultados obtidos evidenciam que os inibidores da síntese e da ação de etileno aumentaram o rendimento de algodão em caroço e de fibras em ambas as estações de crescimento. Os resultados o...

Consequences of waterlogging in cotton and opportunities for mitigation of yield losses

“…Higher waterlogging sensitivity during early reproductive growth in cotton has been notionally linked to the hormone-dependent shedding of young squares observed during abiotic stress ( de Brito et al . 2013 ).…”

“…2010 ). In a 2-year field study, de Brito et al . (2013) recorded a positive effect of AVG and 1-MCP on cotton seed and lint yield.…”

Ethylene Inhibitors Increase Net Assimilation Rate and Cotton Boll Dry Matter Under Drought

“…In this report, the inhibition of ethylene action and/or its synthesis were able to increase its boll dry mass when submitted to water deficit. As has been established by different studies, under abiotic stress cotton plants alters the hormone balance and triggers the activation of pathways involved in these responses, resulting in the abscission of squares and bolls consequently reducing the seed cotton yield and fiber yield (Stewart et al, 2010;Brito et al, 2013). As above described, a common response of cotton plants when submitted to stress is its increased ethylene biosynthesis; and although this comportment is very well established and its role in the regulation of the abscission process in cotton fruit is extensively reported, the relationship of ethylene with boll dry mass across of the reproductive branches via positional plant mapping and its photosynthetic responses to water deficit is scarce.…”

“…In general, this report demonstrates that the ethylene inhibitor applications can mitigate the effects of water deficit on important components yield, such as boll dry mass and total boll per plant, even ethylene inhibitors effects was stronger in boll dry mass compared to boll number. Although the role of ethylene on cotton plants and its interaction with key enzymes, such as sucrose synthase and invertase is not fully understood, positive effects of 1-MCP (Kawakami et al, 2010) and 1-MCP and AVG (Brito et al, 2013) on the physiology and yield of field-grown cotton were demonstrated. When 1-MCP was sprayed during the first flower emission phase on plants submitted to water deficit, there were inhibition of cotton stress response, as evidenced by the low antioxidant activities and higher quantum yield, with consequent increase in the boll weight and seed number per boll.…”

Assessing gene action for hypoxia tolerance in cotton (Gossypium hirsutum L.)

“…The yield penalty resulting from waterlogging may vary between 15% to 80%, depending on the species, soil type and duration of the stress (Zhou, 2010). Cotton is sensitive to waterlogging which results in young square shedding at reproductive stage which is found to be the result of hormonal imbalance (de-Brito et al, 2013). Waterlogging sensitivity in cotton is linked with photosynthetic inhibition (Najeeb et al, 2015).…”