Germination and Seedling Properties of Lotus corniculatus L. Under Simulated Drought Stress

Abstract

Drought is an important abiotic stress factor that reduces agricultural production and yield in many crops, including forage crops, in agricultural areas around the world. Lotus corniculatus L. is the agriculturally crucial perennial legume forage crop that can tolerate moderate drought. However, studies to determine the responses of L. corniculatus to drought are limited. Therefore, this study was carried out to determine the seed germination and early seedling growth properties of L. corniculatus at different PEG6000 induced-drought treatments under in vitro conditions. In order to do this, L. corniculatus (cv. ‘AC Langille’) seeds were planted in MS (Murashige and Skoog/Gamborg) medium containing 0%, 4%, and 8% (w/v) PEG6000 for 14 days. In this study, germination percentage, mean germination time, germination rate index (speed of germination), shoot and root length, root to shoot length ratio, shoot and root fresh weight, shoot and root dry weight, shoot and root dry matter ratio, root shoot dry matter ratio, shoot and root water content and seedling vigor index parameters were measured. Our results showed that increasing drought levels resulted in an overall significant reduction in germination and seedling growth parameters except shortened mean germination time (especially, 4% PEG6000 treatment) and increased shoot and root dry matter ratio at higher (especially, 8% PEG6000 treatment) drought levels. When important growth parameters such as length, fresh and dry weight, dry matter ratio and water content, which show the development of root and shoot organs, are evaluated together, it has been determined that the root is negatively affected by drought stress at a higher rate. Based on these data, it can be concluded that the L. corniculatus will suffer a high yield loss under the drought stress at the osmotic potential (-1.03 bar) created by 8% PEG6000 treatment.