Univariate and multivariate statistical tools for in vitro conservation of citrus genotypes

Abstract

This study aimed to evaluate the influence of the growing environment on the in vitro conservation of citrus genotypes obtained from the Active Citrus Germplasm Bank of Embrapa Cassava and Fruit. The study used multivariate statistic tools in order to improve the efficiency in the analysis of the results. Approximately 1-cm of length microcuttings from plantlets derived from ten genotypes previously cultured in vitro were inoculated in test tubes containing 20 mL of WPM culture medium supplemented with 25 g L^-1 sucrose, solidified with 7 g L^-1 agar and adjusted to a pH of 5.8, and maintained under three environmental conditions for 180 days. The experiment was carried out in a completely randomized design in a split-plot in the space, with 15 replications. The results indicate that the principal component analysis is an effective tool in studying the behavior of different genotypes conserved under different in vitro growing conditions. The growing conditions of 22±1°C, a light intensity of 10 μmol m^-2.s^-1 and a 12 hours photoperiod was the most adequate for reducing the growth of in vitro conserved plants, increasing the subculture time interval while keeping the plants healthy.