The Research Of Growth And Mycorrhizal Of Different Wheat Varieties Released In Two Periods

The wheat varieties cultivated in two different periods were selected in this study as research object, which included earlier cultivated variety(B1, cultivated in between 1980 and 1990) and modern variety(B2, cultivated during 2008-2014). By establishing the trials of sterilized vaccination and different types of fertilization, the impacts of different fertilization treatments including no fertilizer(CK), nitrogen fertilizer(N), phosphorus fertilizer(P) and nitrogen-phosphorus fertilizer(NP) on the wheat varieties cultivated in two different periods were investigated through comparing the differences in plant SPAD,photosynthetic rates, biomass, root-stem ratio, mycorrhiza infection rates and mycorrhiza dependency as well as nitrogen and phosphorus concentration. The purpose of this study was to screen out highly resistant and little fertilizer needed wheat varieties, thus mitigating the application of chemical fertilizers while improving the yield of wheat.Main results are as followings:(1)The photosynthetic rates, biomass and yield of B2 under N treatment were significantly higher than those of B1 respectively by 4.04%, 12.7% and 17.8%. And the photosynthetic rates, biomass and yield of B2 under N treatment were significantly higher than those of B1 respectively by 5.37%, 8.77% and 17.3% under P treatment. Under NP treatment, the photosynthetic rates, biomass and yield of B2 under N treatment were significantly higher than those of B1 respectively by 5.61%, 10.9% and 18.5%.Both under N and NP treatments, the nitrogen and phosphorus concentration in wheat leaves and stems of B2 were significantly higher compared with those of B1. And there were no significantly differences between the nitrogen and phosphorus concentration in wheat leaves and stems of B1 and B2 under CK and P treatments.(2) The cultivation process decreased the mycorrhiza infection rates during jointing stage. Compared with those of B1, the mycorrhiza infection rates of B2 in jointing stage dropped by 5.3%. N and NP treatments significantly increased the mycorrhiza infection rates of B1 and B2 during jointing stage, while fertilization imposed no impacts on mycorrhiza infection rates during mature period. Compared with those under CK, the mycorrhiza infection rates of B1 in jointing stage under N and NP treatments were respectively improved by 16.8% and 4.3%, and the mycorrhiza infection rates of B2 during jointing stage were respectively increased by 23.8% and 8.18%.There were no significant differences between the mycorrhiza infection rates of B1 and B2 during mature period.(3)The treatment of AMF significantly reduced the leaf SPAD, photosynthetic rates, biomass and yield compared with NAMF.(4) Compared with those under NAMF, the leaf phosphorus and nitrogen concentration, the stem phosphorus and nitrogen concentration in jointing stage as well as the leaf phosphorus and nitrogen concentration, the stem phosphorus and nitrogen concentration in mature stage under AMF were significantly higher respectively by 39.8%,17.4%, 52.8%, 17.1%, 35.0% and 17.9%.In conclusion, mycorrhiza could inhibit the SPAD, photosynthetic rates, biomass and yield of wheat, and improve the nitrogen and phosphorus concentration in wheat leaves and stems. Under the circumstances of low fertility, modern cultivation process could significantly improve the photosynthetic rates, biomass and yield of wheat, except those under CK. When applied with nitrogen and phosphorus fertilizers, the nitrogen and phosphorus concentration in leaves and stems of modern wheat variety were significantly higher than those of earlier cultivated variety. However, these advantages of modern variety were not shown under low fertility condition. The mycorrhiza infection rates of modern variety were significantly lower than those of earlier cultivated variety while no significant differences were found between their mycorrhiza dependency. The application of nitrogen and phosphorus fertilizers could significantly increase the mycorrhiza infection rates in jointing stage. When the fertility is low, choosing the modern wheat variety with relatively low level of fertilization could facilitate the improvement of yield,providing an enlightening reference for the cultivation and screening process of wheat varieties.