Unique shape of Trichosanthes pilosa seed and its biological meaning

Abstract: Trichosanthes.pilosa(=T. pilosa) commonly known as Japanese snake gourd is a plant in Cucurbitaceae family. They are adapted to grow in tropical monsoon, wet tropical, and humid subtropical climates across regions in East Asia, Southeast Asia, Northeast India, and North Australia. The species has uniquely shaped seeds resembling a mantis head, which is also uncommon within the same genus Trichosanthes. The seed has three chambers: one in the middle where the embryo is positioned – named middle chamber, and one on each side, which are filled with white fibrous material – named side chambers. Despite its uniqueness, the function and biological meaning of this shape remains unknown. This project aims to understand the biological meaning and adaptation underlying this shape. I hypothesize that seed’s shape serves to enhance water absorption but also to retain water during the susceptible germination phase. This could possibly have evolved in response to past tropical monsoon climates, characterized by alternating dry and wet seasons. To explore the hypothesis, two sub-hypotheses were tested experimentally. The first sub-hypothesis examined the difference in water absorption and dehydration curve of T. pilosa seeds with sealed side chambers compared to untreated T. pilosa seeds as a control. The results showed that there is a significant difference in water bearing capacity between control seeds and side chamber-sealed seeds. This indicates the influence of side chambers on the seed's water absorption capacity. The second sub-hypothesis examined germination rates of seeds after different treatments - control seeds with no treatments, seeds that are treated with sulfuric acid, seeds with sealed side chambers with wax, and seeds treated with both wax and sulfuric acid. The statistical analysis revealed no significant differences in germination rates among various treatments, except for a slightly notable distinction between control seeds and those treated with wax and sulfuric acid. However, these statistical outcomes could be attributed to error, potentially arising from the low germination rate.