Developmental plasticity confers adaptive traits to Argentinian weedy rice to become extremely successful weeds.

ISABELLA RAMPOLDI; LUCRECIA BONELL; ALDANA GÓMEZ; ALEJANDRO PRESOTTO; MARÍA CREPY; GABRIELA A AUGE

Congreso; XXXIII Argentinian meeting of Plant Physiology (Reunión Argentina de Fisiología Vegetal); 2021

Sociedad Argentina de Fisiología Vegetal

Agricultural weeds are responsible for a large proportion of crop yield losses worldwide. In particular, weedy rice (a closely related weed to rice, Oryza sativa) can cause complete loss of the crop and lead producers to abandon weed-infested fields for years when left unattended. In Argentina, weedy rice invades the whole rice producing area, imposing the need for more effective management strategies for local producers in the short term. Therefore, understanding local weedy rice characteristics is of importance to develop more sustainable weed control programs. Using four weedy biotypes and two cultivated genotypes, we evaluated weedy rice developmental plasticity (flowering time and seed production) under two contrasting environments (control and high temperature), and assessed progeny seed germination. Flowering time significantly differed between the weedy biotypes and the cultivated genotypes. Even more, weedy rice plants showed a longer flowering period than the cultivated genotypes (~1 month vs 1 week, respectively). The environment during the reproductive stage did not affect seed production of both cultivated and weedy genotypes. However, the environment during reproductive growth influenced the germination response of progeny seeds of cultivated and weedy genotypes in a pattern dependent on genotype and incubation temperature (significant Maternal Environment x Genotype x Incubation Temperature interaction). Nevertheless, weedy rice seeds showed higher variability in dormancy levels. Altogether, our results show that Argentinian weedy rice biotypes have increased developmental plasticity that may result in extremely adaptive phenotypes, suggesting their control would soon require multiple and potentially more expensive management programs in the region.