A quantitative description of seed wáter content during induction into secondary dormancy in Polygonum aviculare seeds

CRISTIAN MALAVERT; BATLLA DIEGO; BENECH-ARNOLD, ROBERTO

Congreso; 12th Conference of the International Society for Seed Science; 2017

The number of established seedlings and time of weed emergence is strongly related to the dynamics of dormancy release of the seed-bank. Changes in the level of dormancy in the seed-bank are determined through the effect of several environmental factors acting simultaneously. The main regulatory factor is temperature whose effect is modulated by soil water content. Indeed, there is evidence of the existence of a threshold water content of 15 % above which the rate of dormancy release rate in Polygonum aviculare seeds increases linearly with seed water content (SWC) until reaching a maximum around 30 % SWC. However, it is not known exactly how soil water content regulates the induction into secondary dormancy in P. aviculare seeds. The aim of this work was to study the effect of SWC during induction into secondary dormancy in P. aviculare seeds. To measure the effect of SWC during induction into secondary dormancy the seeds were first stratified at 5 ºC during 100 days (thermal stratification conditions for dormancy release) and then, the seeds were induced into secondary dormancy at 20 ºC for 12 days (initial SWC was 34 % before induction), under controlled conditions of relative humidity (%RH) of 5, 15, 61 75, 88, 96, 100 %RH and imbibed seeds (3 and 5 ml in distilled water); under these conditions moisture content values in the seeds of 6.7, 7.6, 11.4, 13.4, 15.8, 22, 29.8, 35.4, 45.7 and 67 %, were obtained. The results showed that seeds with SWC values below