Effects Of The Physiological And Biochemical Characters Of Kiwifr Uit Growed On Different Stocks With Waterlogging Treatment

The two-year-old ‘Hongyang’ kiwi seedlings grafted on conventional rootstocks(Delicious kiwi fruit seedlings) and new rootstocks(Actinidia valvata Dunn. cutting seedlings) were used in this study.We investigated the effect of complete still-water on the growth and physiological and biochemical characteristics of the ‘Hongyang’ kiwi seedlings with two rootstocks. The aim is to study the mechanism of waterlogging resistance in the new kiwi stock and provide a theoretical guidance for its application in production. The main results are as follows:1. The mature leaf area of ‘Hongyang’ kiwi grafted on the new rootstocks was 6.4% larger than that of the conventional rootstocks. After flooding treatment for 12 days, the ‘Hongyang’ kiwi seedlings of conventional rootstocks started to die and then all died after 20 days. While the growth of leaves and branches of the ‘Hongyang’ kiwi seedlings grafted on new rootstocks was still normal in 20 days.Furthermore, the root of conventional rootstocks all became black, erosion and excoriation after flooding treatment for 12 days and then all died after 20 days. On the contrary, the root of the new rootstocks was still alive, and a small amount of milk white new roots appeared.2. Under waterlogging stress, the ‘Hongyang’ kiwi root activities of two kinds of rootstocks were both decreased with the increase of flooding time. But the decline range of the new type of stocks was significantly less than that of conventional rootstocks. After flooding 6 days, the root activity of the conventional rootstocks and the new rootstocks were decreased by 82.6% and 59.8% respectively.3. The alcohol dehydrogenase(ADH) activities of ‘Hongyang’ kiwi root of two kinds of rootstocks were both showed downward trend after the first rise with the increase of flooding time. But jump time of the ADH activity of new rootstocks appeared late, which was beneficial to improve the plant waterlogging resistance.4. In flooding process, the superoxide dismutase(SOD) activity of the new rootstocks were first increased and then decreased, while the conventional rootstocks was always decreased; The APX activity of the conventional rootstocks were first increased and then decreased, while the new rootstocks was always increased.5. In flooding process, the malonaldehyde(MDA) content of ‘Hongyang’ kiwi with two kinds of rootstocks were both increased. The conventional rootstocks and the new rootstocks were increased by27.7% and 20.7% respectively. The contents of free proline(Pro) in ‘Hongyang’ kiwi of two kinds of rootstocks were both increased with the increase of flooding time.6. After flooding treatment for 12 days, The decrease rate of effective quantum yield(Y(Ⅱ)) and photochemical quenching coefficient(qP) in ‘Hongyang’ kiwi leaves grafted on new rootstocks were14.9% and 3% lower than that of conventional rootstocks respectively. The decrease rate of electron transfer efficiency(ETR) in the new rootstocks was significantly smaller than the conventional rootstocks. Non photochemical quenching coefficient(qN) of two rootstocks were both increased first and then decreased, but the ascending range of conventional rootstocks was obviously larger. Thevariation of chlorophyll fluorescence parameters indicated that the photosynthetic function of‘Hongyang’ kiwi leaves grafted on new rootstocks was much stronger than conventional rootstocks.