Kinetics of water uptake in italian common bean ecotypes

The study was conducted on 98 populations belonging to 62 Italian common bean ecotypes. The comparison of the hydration index plots relative to the 98 tested samples evidenced the existence of three distinguishable groups. The first one correspond to very slow water uptake being the hydration index after 5h of soaking inferior to 30 %. The second group was characterised by intermediate water uptake (hydration index at 5h ranging from 30 to 50%), while the third one comprised the samples with very fast water uptake being the hydration index at 5h more than 50%. Polynomial equations of different degree fitted the curves with a good correlation (R2 > 0.996). Equations of second, third and fourth order needs to be used to fit slow, intermediate and fast water uptake, respectively. Similarly, the trend of water uptake (slow, intermediate or fast) did not changed by the year-to-year. Among the tested ecotypes only 8 were characterised by significant year-to year variation.