Water Deficit during the Reproductive Period of Grass Pea (Lathyrus sativus L.) Reduced Grain Yield but Maintained Seed Size

Abstract

The grain legume grass pea (Lathyrus sativus L.) is adapted to drought-prone environments, but the extent and mechanisms of its tolerance are not well understood. In a pot experiment, water deficit was imposed on plants by withholding water from first flowering until predawn leaf water potential (LWP pd ) was )3.12 MPa. Water deficit reduced dry matter, seed yield, harvest index and water use efficiency by 60 %, 87 %, 67 % and 75 %, respectively, when compared with the controls. Flower production stopped when LWP pd fell to )1.8 MPa. At LWP pd )1.5 MPa, only 25 % of flowers resulted in filled pods (compared with 95 % filled pods in the control) with the rest aborted as flowers (48 %) or pods (27 %). Filled pods had more aborted ovules than controls, resulting in 29 % less seeds per pod. Water deficit reduced pollen viability, germination and the number of pollen tubes reaching the ovary by 13 %, 25 % and 31 %, respectively. Emergence from seeds produced from water-deficient plants was 21 % less than controls, but seedling shoot dry mass was 18 % higher, in accordance with the 19 % higher seed mass. The sensitivity of flowering to drought limited pod numbers but enabled plants to retain existing pods and develop near-normal seeds with low b-N-oxalyl-l-a-b-diaminopropionic acid toxin concentrations. This trait is useful for farming systems reliant on harvested seed for the next crop and in cases where seed size influences the value of the product.

Estimation of genetic components for plant growth and physiological traits of wheat (Triticum aestivum L) under normal and stress conditions

“…Eight seeds were sown in each bag and after germination seedlings were thinned to four. Drought stress was imposed by withholding water as done by Gusmao et al (2012).…”

Déficit Hídrico E Produção Do Tomate Cultivado Em Ambiente Protegido

“…Resultados semelhantes foram obtidos por Santana et al (2010), em experimento com a cultura de tomate em que foi observado que tanto o déficit quanto o excesso de água foram prejudiciais ao crescimento da planta. Harmanto et al (2005), verificaram que o tratamento irrigado com 75% da evapotranspiração da cultura apresentou a maior altura da planta de tomate, da ordem de 1,49 m, aos 75 dias após o transplantio.…”

“…Sincik et al (2008), verificaram que a área foliar da soja reduziu significativamente com o aumento do déficit hídrico em todas as fases de avaliação, bem como a produtividade. ) em função das tensões de água no solo Com relação à matéria seca da parte aérea da planta pesquisas com diversas culturas tem demonstrado que a mesma reduz com o aumento do déficit hídrico (GUSMAO et al, 2012;COSTA et al, 2008;ISSARAKRAISILA et al, 2007).…”

The Ideotype for Seed Size: A Model Examining the Relationship between Seed Size and Actual Yield in Pea

“…Yield potential is thought to be partially determined by 2 International Journal of Agronomy seed size, and numerous studies have tried to understand the relationship between seed size and yield in pea and other pulses with contradictory results [1,[4][5][6][7][8][9]. A lack of correlation between seed size and yield was found in grass pea under drought conditions [5]. In chickpea, a positive correlation was found between seed size and yield, but no effect was seen in lentil [4].…”