Comparision Study On The Characters Of Growth And Relative Physiology Of Virus-Eliminated Plants From Tissue Culture And Its Progenies Of Lipu Taro (Colocasia Esculenta Schoff)

With a local variety from Town Qingshan, Lipu County, as the control, virus-eliminated plants from tissue culture of the tip buds of corms(H1) and those of their second(H2) and third (H3) generations of Lipu taro(Colocasia esculenta Schoff) were used as the plant materials in this experiment. The characters of growth and relative physiology were studied comparatively for the four sources of taro plants. The results were as follows.1. The plants of the H3 generation showed higher in plant height, maximum length and width of leaves than those of the control, but those of H2 generation lower than those of the control, and those of the H1 generation the lowest. There was no difference in leaf number among the different sources of plants. The leaves lived longer for the plants of H1 generation, and they displayed certain vigor at the late stage of the mother corm development.2. The average weight per month of corms of virus-eliminated sources increased faster than that of the control.3. The plants of virus-eliminated sources distributed more photosynthates to the corms at the early stage of corm expansion as compared to the control.4. The plants after virus-eliminated treatment including H2 generation and H3 generations increased the chlorophyll content, and those of H3 generation showed the highest. They also improved the net photosynthetic rate, gas conductance and evaporation in their leaves to those of the control.5. For the chlorophyll fluorescence including kinetics, the plants aftervirus-eliminated treatment including the HI generation and H3 generations increased the minimal fluorescence(Fo). They also showed higher efficiency of primary light energy conversion by PSII(Fv/Fm),activity potential of PSII(Fv/Fo), photochemical quench(qP) and non-photochemical quench (qN) as compared to those of the control during the late stage.6. The plants after virus-eliminated treatment including the H2 generation and H3 generations showed higher activity of nitrate reductase, and those of H1 generation the highest. They also showed higher total phosphorus and potassium in the leaf stalks and total phosphorus of leaves, but no significant difference in soluble sugar content in the leaves and the leafstalks as compared to those of the control.7. The plants after virus-eliminated treatment including the H2 generation and H3 generations increased the yield and improved quality of the conns of Lipu taro, and the H3 generation showed the best. The plants of the H2 generation and H3 generations produced significantly higher yield per hectare and higher fresh weight of the mothers conns than those of the control.Considering all of the above, we suggest that it would be the best to use the corms of H1 for propagation, and those of H2 and H3 for commercial food production.