Effects of nitrogen on plant-microorganism interaction

Özet

Kok bolgesi, bitki koklerini cevreleyen topraklarda yer alan biyolojik acidan aktif bir bolgedir. Rizosferdeki kokmikroorgaizma etkilesimi bitki ve mikroorganizmanin her ikisi icin faydali olabilecegi gibi, hic faydasi da olmayabilir. Bitki ve mikroorganizma arasindaki etkilesimi etkileyen faktorler nelerdir? Etkilesimi incelemek amaciyla capraz testler yapildi. Azot gradyanti boyunca bitkiler mikroorganizmalarla incube edildi. Bir kismi incube edilmeden birakildi. Sonuclar, azotun kok-mikroorganizma iletisiminde aktif bir rol oynayabilecegini ve bitki buyumesinde onemli bir etkisi olabilecegini gostermistir. Azot icermeyen ortamda, mikroorganizmalar bitki buyumesini etkilememistir ve istatistiksel bitki-mikroorganizma etkilesim yogunlugu sifira yaklasmistir. Ancak, dusuk azotlu ve optimum azotlu ortamlarda, steril topraktaki bitki biyokutlesi steril olmayan topraktakinden daha fazlaydi. Bitki-mikroorganizma etkilesim yogunlugu negatifti. Yuksek azot icerikli ortamlarda, steril olmayan topraklardaki bitkiler steril topraklardaki bitkilere gore daha iyi buyumuslerdir. Bitkimikroorganizma etkilesim yogunlugu pozitifti. Ek olarak, bitki buyumesi, hem steril hem de steril olmayan topraklarda mikroorganizma biyokutlesini onemli olcude artirmistir.

Abstract

The rhizosphere is a biologically active zone in the soil around the roots of plants. Rootmicroorganism interaction in the rhizosphere can be both beneficial to the plant, the microorganisms or to neither of them. Which factors affect the interactions between plants and microorganisms within this crowded rhizosphere? In order to investigate their interaction, contrasted tests were carried out. The plants across the nitrogen gradient were incubated with and without microorganisms. Results showed that nitrogen might play an active role in rootmicroorganism communication, and thus have an important effect on plant growth. With no nitrogen nutrient medium, microorganisms did not affect the plants growth obviously and the statistical interaction intensity of plant-microorganism approached zero. However, with a low level of nitrogen nutrient medium and an optimal nitrogen nutrient medium, plant biomass in sterile soil was more than plant biomass in non-sterile soil. The interaction intensity of plantmicroorganism appeared negative. With a high level of nitrogen nutrient medium, plants grown in a non-sterile soil had better growth than plants grown in sterile soil. The interaction intensity of plant-microorganism appeared positive. Additionally, plant growth significantly increased the microorganism biomass both in the sterile soil and non-sterile soil.

Anahtar kelimeler: azot,kökler,büyüme oranı,toprak kimyası,bitkiler,mikroorganizmalar,etkileşim