Dormancy breaking methods and priming techniques to improve seed germination in gynandropsis gynandra (L.) briq syn cleome gynandra L. (Cleomaceae).

Abstract

Gynandropsis gynandra, commonly known as spider plant, is a leafy vegetable that belongs to the Cleomaeae family. Spider plant is used for its medicinal properties, but also as a nutritional supplement, and an animal (e.g., cows) feed. Farmers experience low and uneven germination when planting this species that studies ascribed to physiological dormancy which leads to low and uneven germination. The study was conducted to understand mechanisms involved in breaking dormancy in spider plant seeds. The objectives were (a) to determine the effects of packaging materials and storage period on seed germination, and (b) to determine the effects of priming agents and duration on seed germination of G. gynandra. These objectives were achieved through two experiments based on six accessions of G. gynandra originated from West Africa, East Africa, and Asia. In the first experiment, the seeds were stored for four months at room temperature of 25℃ in brown paper bags, aluminium foil paper, and black polystyrene bags. After every storage period, the seeds were tested for electrical conductivity (EC), viability using tetrazolium chloride and germination ability to study the effects of storage period and packaging material on seed viability and vigor of G. gynandra. In the second experiment, the six accessions were subjected to two priming agents, PEG-4000, and distilled water, and tested for germination. Final germination percentage (FGP), mean germination time (MGT), mean germination rate (MGR), coefficient of the velocity of germination (CVG), and radicle length (RL) were recorded. Data analysis was done using Genestat version 20th edition (VSN International, United Kingdom) at a 5% level of significance. The study showed that G. gynandra fresh seeds displayed physiological dormancy which can be broken by storing seeds for at least two months depending on the genotype in aluminium foil paper. In this study, seed priming with PEG-4000 and distilled water had no effect on seed germination of G. gynandra.