Effect of different temperatures for in vitro conservation of cassava (Manihot esculenta Crantz) germplasm

Abstract

The objective of the present work was to evaluate in vitro growth of cassava accessions under different temperatures to improve protocols for germplasm conservation. Acclimatized chambers were tested at 18 °C, 20 °C and 22 °C, and again at 22 °C in conservation room (control) in five accessions: Mandioca João Grande (BGM1325), Fécula Branca (BGM1632), BRS Kiriris (BGM1728), S/N (121) (BGM2004) and BRS Prata (BGM2019). After 90 days of distance, the following were evaluated: shoot height (cm), number of sprouts and microcuttings, number of green and senescent leaves, fresh and dry weight of shoots and roots (g). The experiment was performed under a completely randomized design in factorial scheme 5(accessions) x 4(temperatures), with 20 replicates. All data were submitted to the F test ANOVA and evaluated by the Tukey and Scott-Knott tests at 5% probability. The control temperature promoted lower mean values for plant shoot height, with emphasis for accessions BGM1325, BGM1632 and BGM2019. In a general manner accessions BGM1325, BGM1632 and BGM2019 showed lower SH, with the first and BGM2004 outstanding with the best results for lower NSL and higher NGL.