Growth and biomass yield responses of Sphenostylis stenocarpa (Hochst. Ex A. Rich.) Harms accessions to waterlogging stress

Abstract

Effects of waterlogging on the growth of six accessions of Sphenostylis stenocarpa were investigated. There accessions were TSs-5, TSs-7, TSs-8, TSs-9 TSs-10 and TSs-11. After growing S. stenocarpa for 4 weeks, results indicated that waterlogging significantly (p=0.05) reduced its growth parameters of S. stenocarpa. For shoot length; TSs-9 recorded the highest value (48.27±2.92 cm) above its control while TSs-11 (17.96±1.13 cm) had the lowest value. For petiole length, TSs-9 (3.62±0.33 cm) recorded the highest value while TSs-8 (0.93±0.93 cm) recorded the lowest value. Internode length had TSs-7 (6.10±0.78 cm) had the highest value while TSs-8 (2.87±2.87 cm) had the lowest value. The total photosynthetic pigment measurement showed that TSs-5 (45.0±0.65 mg/kg) with the highest value and TSs-8 (33.37±14.00 mg/kg) had the lowest value. For leaf area, TSs-7 (25.73±4.21 cm2) had the highest value while TSs-11 (16.13±2.82 cm2) recorded the lowest value. Total Fresh Weight (TFW), TSs-7 recorded the highest value (4.96 g) while TSs-8 recorded the lowest value (1.75 g). Root Fresh Weight (RFW), Tss-5 was observed to have the highest value (1.44 g) while Tss-11 recorded the lowest value (0.56 g). However, at 2 weeks after planting the effect of waterlogging stress on the growth parameter was not significant. The reduction in the growth of S. stenocarpa as a result of waterlogging stress might be due to the detrimental effect of flooding on O2 availability for plant cells and other plant metabolic activities of the plant. In areas with waterlogged soil conditions, S. stenocarpa should not be cultivated as it has poor and relatively low tolerance towards withstanding the impact of waterlogging; however, accession TSs-9 showed promising waterlogging tolerance ability.