Crescimento de mudas de cafeeiro inoculadas com fungos micorrízicos arbusculares

Abstract

RESUMOPropôs-se, neste trabalho, analisar o crescimento de mudas de cafeeiro inoculadas com fungos micorrízicos, por meio da análise de crescimento de plantas. O delineamento adotado foi inteiramente casualizado, em esquema fatorial 2x6, sendo mudas inoculadas e não inoculadas e seis épocas de avaliação, com seis repetições. Utilizaram-se sementes de Catuaí Vermelho IAC 99, desinfestadas e geminadas em areia autoclavada. Após 75 dias, no ato da repicagem, metade das mudas foi inoculada aplicando-se esporos das espécies Glomus clarum e Gigaspora margarita. Na época da inoculação (0) e aos 30, 60, 90, 120 e 150 dias foram mensuradas a altura e a área foliar, além de posterior determinação de massa seca foliar e total. Os dados foram extrapolados para determinação de medidas não lineares para análise de crescimento. De modo geral, as plantas inoculadas apresentaram efeito negativo no início do crescimento mas ao final do período experimental possuíam características de crescimento superiores às mudas não inoculadas. A análise de crescimento possibilitou uma compreensão melhor da associação, além de constatar que, apesar do maior investimento na morfologia para captação de energia, não ocorreu aumento da taxa de assimilação líquida podendo-se considerar que, inicialmente, os fungos representaram dreno de assimilados mas no final as mudas inoculadas apresentaram crescimento superior. Conclui-se que, inicialmente, a associação seja considerada dreno de assimilados da planta que ainda não possuem área foliar para manutenção da associação e sofrem queda da taxa fotossintética líquida. Este efeito se extingue e resulta em benefício para as mudas, no final do período de produção. Palavras-chave: Coffea arabica, Gigaspora margarita, Glomus clarum Growth of seedlings of coffee inoculated mycorrhizal fungi ABSTRACTThe objective of this work is to analyze the growth of coffee seedlings inoculated with mycorrhizal fungi, through the analysis of plant growth. The experimental design was completely randomized in a 2x6 factorial design, with control and inoculated seedlings six evaluation periods, with six replications. Catuaí Vermelho IAC 99 seeds were desinfested and germinated in autoclaved sand. After 75 days, at the time of transplanting, half of the seedlings were inoculated by applying spores of species Glomus clarum and Gigaspora margarita. At the time of inoculation (0) and at 30, 60, 90, 120 and 150 days plant height and leaf area were measured, and subsequent determination of total and leaf dry mass. The data were extrapolated to determine the measures of non-linear growth analysis. In general, the inoculated plants showed a negative effect on early growth, but at the end of the experiment had superior growth than uninoculated seedlings. Growth analysis enabled a better understanding of the association, and found that despite the increased investment in morphology for energy harvesting, there was no increase in net assimilation rate and may consider that initially fungi represented drain assimilated, but in the end the...

Selection of mycorrhizal fungi for the initial growth of Albizia polycephala

“…This was true for inoculation with S. calospora if observed the number of favored characteristics (Table 2), but false for the other inoculants. The lack of clarity in this regard comes from nutritional imbalance that can occur in the early stage of seedling growth, where the fungus species is more favored (by assimilates) than the plant (for all nutrients needed), resulting in low growth (França et al, 2014).…”

ARBUSCULAR MYCORRHIZAL FUNGI IN SEEDLING FORMATION OF BARBADOS CHERRY (Malpighia emarginata D.C.)

“…The data of these authors corroborate with the results obtained in this work for barbados cherry AGR, even with different plant species, indicating that some isolated or combined AMF species interfere in this growth rate, due to lack of specificity or higher energy cost required for plants to maintain symbiosis. Initially, mycorrhizal symbiosis is a drain for seedlings, but over time, this effect is reduced and the seedlings begin to benefit from the association (FRANÇA et al, 2014).…”

Mycorrhizal fungi increase coffee plants competitiveness against Bidens pilosa interference

“…AMF are responsible for increasing seedling growth (França et al 2014), better water and nutrient absorption (especially low solubility ones), and tolerance to adverse environmental factors (Smith & Smith 2012). However, in the conventional seedling production, plants are not inoculated with AMF, and natural colonization is slow.…”