Phenotyping for resistance to pre-harvest sprouting in grain sorghum (Sorghum bicolor L. Moench)

M. VERÓNICA RODRÍGUEZ; ARATA GONZALO JOAQUÍN; BENECH-ARNOLD R.L.; PEDRO PARDO; SANTIAGO RENTERÍA

Montpellier

Congreso; SORGHUM IN THE 21ST CENTURY - GLOBAL SORGHUM CONFERENCE; 2023

CIRAD - IRD - CERAAS - Sorghum ID, France

Pre-harvest sprouting (PHS) is an agronomic problem. It is related to the disruption of seeddormancy in modern crops, a key adaptive trait in wild species. Reduced grain dormancy while still inthe mother plant in combination with rainy, moist conditions cause the grains to imbibe, and theseed germination process is triggered. This leads to the hydrolysis of starch reserves and embryoelongation outside the pericarp, exposing the grain to fungi attack and to lose desiccation tolerance.In its worst version (i.e. where viability is lost), sprouting results in grains that are no longer suitablefor malting, sowing of a new crop, and have to be destined to other less profitable end-uses.Genetic predisposition to PHS has not been properly screened during sorghum improvement.We propose a protocol suitable for phenotyping and classifying sorghum genotypes according totheir susceptibility to PHS. This protocol addresses the germination response of detached grains,and also of grains attached to the intact panicle under standard, laboratory conditions. Laboratoryresults are also compared with records of natural sprouting in the field. We also explored possibleassociations between grain dormancy and morphological traits: grain pigmentation, glume size andcolor, plant height and time to flowering