Methods to assess the viability of cryopreserved Jatropha curcas L. seed germplasm

Abstract

ABSTRACT Jatropha curcas L. is a plant species with many potential applications, especially medicinal uses (hypoglycemic, anti-inflammatory, haemostatic, healing, anti-tumor). The objective of this study was to test germination in moist paper rolls for whole seeds and in vitro for excised embryonic axes, in an attempt to identify the best method to assess the quality of J. curcas seed germplasm, cryopreserved with different water contents. The experimental sample with a 6.2% moisture content (MC) was divided in subsamples which were hydrated and dehydrated for 0 (control), 4, 8, 11 and 24h. The initial germination percentages were 63% for whole seeds and 81% for excised embryonic axes. After exposure to liquid nitrogen (LN), germination percentages were 48% (whole seeds) and 57% (excised embryonic axes). There was no significant difference between germination percentages in embryonic excised from seeds subjected or not subjected to freezing, with different MC. In contrast, there was a reduction of the whole seed germination percentage when exposed to LN (contrast = 0.17, standard error = 0.04, t = 4.09, p = 0.001) and not for the hydration and dehydration treatments. The methodology based on in vitro cultures of the embryonic axis isolated from seeds stored in LN with distinct MC values was more efficient than the standard germination test to evaluate the viability of J. curcas seeds before and after LN storage.

Keywords

• seed
• embryonic axis
• cryopreservation
• Jatropha curcas