Physiological quality and seed respiration of primed Jatropha curcas seeds

ABSTRACT Seed deterioration is a natural and irreversible process. Nevertheless, seed priming with water and antioxidants can minimize oxidative damage in oilseeds, resulting in attenuation of seed deterioration. The objective of this assay was to evaluate seed priming on respiratory activity of Jatropha curcas submitted to accelerated aging. Seeds from two provenances (Janauba and Pedro J. Caballero) were submitted to three priming treatments (control, immersion in deionized water, and with 750 µmol L-1 of ascorbic acid) and treated for accelerated aging at 41 °C for 72 h. The results showed that the priming of J. curcas seeds promoted tolerance to accelerated aging. Primed seeds, with ascorbic acid from Janauba and deionized water from Pedro J. Caballero, resulted in a higher percentage of normal seedlings, and increased germination speed index and seed respiration. The decline of physiological quality of J. curcas seeds after accelerated aging is directly associated with a reduction in respiratory activity that is related to seed moisture content.

摘要：种子劣变是一种自然且不可逆的过程。通过水与抗氧化剂进行种子引发（seed priming），可最大程度降低油料种子的氧化损伤，进而缓解种子劣变。本试验旨在评估种子引发对加速老化（accelerated aging）条件下麻疯树（Jatropha curcas）呼吸活性的影响。试验选取两个种源（Janauba与Pedro J. Caballero）的麻疯树种子，设置三种引发处理：对照组、去离子水浸种处理以及750 μmol·L⁻¹抗坏血酸处理，随后将种子置于41℃环境中进行72小时加速老化处理。结果表明，麻疯树种子经引发处理后可提升其对加速老化的耐受性。其中，源自Janauba种源经抗坏血酸引发的种子，与源自Pedro J. Caballero种源经去离子水引发的种子，不仅正常幼苗百分率更高，同时发芽速度指数与种子呼吸活性均有所提升。加速老化后麻疯树种子生理品质的下降，与呼吸活性的降低直接相关，而呼吸活性又与种子含水量密切相关。