Arbuscular mycorrhiza increased the activity of a biotrophic leaf pathogen - is a compensation possible?

Abstract

Arbuscular mycorrhizal barley-plants were more susceptible to the obligate biotrophic shoot pathogen Erysiphe graminis f. sp. hordei. In experiments under greenhouse and open-air conditions on leaves of mycorrhizal plants, the sporulation rate of the mildew fungus was more than twice that on control plants. However, mycorrhizal plants suffered less than non-mycorrhizal plants in terms of grain number, ear yield and thousand-grain weight. Disease-yield-relationship analysis showed that the symbiosis neutralised the positive correlation between disease severity and yield loss (up to 25% infected leaf area tested). After mildew infection, nitrogen in ears of nonmycorrhizal barley was higher because of an impaired starch accumulation during grain filling. In mycorrhizal plants, leaf disease did not impair either the quantity or quality of grain yield. This improved compensation in mycorrhizal plants was related to maintained photosynthetic capacity and a delay in pathogen-induced senescence. Thus filling of long-term storage pools (fructans in internodes) and consequently reallocation of these reserves during grain filling was improved. The results suggest that higher availability of energy and material during grain formation, together with longer physiological activity, were the basis of yield maintenance and, therefore, expression of mycorrhiza-induced tolerance towards the pathogen.

The endophytic fungus Piriformospora indica reprograms barley to salt-stress tolerance, disease resistance, and higher yield

“…Abiotic-stress tolerance can be evoked in crops by the exploitation of worldwide abundant endophytic arbuscular mycorrhiza fungi, which live in reciprocally beneficial relationships with Ϸ80% of land plants (4). However, mycorrhizal plants, albeit effective against many root diseases (5, 6), often show enhanced susceptibility to biotrophic leaf pathogens (7,8). On the other hand, ascomycete endophytes have been frequently reported to protect against plant pathogens and pests.…”

Effect of mycorrhizal inoculation on development and flowering of Tagetes patula L. ‘Yellow Boy’ and Salvia splendens Buc’hoz ex Etl. ‘Saluti Red’

“…Studies conducted worldwide show that mycorrhization in numerous plant species has an advantageous effect on chlorophyll content [19][20][21]. An elevated chlorophyll content suggests a more intensive course of photosynthesis, which was confirmed by Gernns et al [22]. In turn, as it was reported by Dixon et al [23], different fungal species have a varied effect on the intensity of this process.…”

Penekanan Perkembangan Penyakit Bercak Ungu pada Bawang Merah oleh Cendawan Mikoriza Arbuskula

“…Hal ini dikarenakan CMA dapat meningkatkan kemampuan bawang merah dalam menyerap air dan unsur hara yang sangat diperlukan dalam masa awal pertumbuhan tanaman (Goltapeh et al 2008). Bawang merah memiliki perakaran yang dangkal dan kasar sehingga pupuk N, P, dan K yang diaplikasikan di sekitar perakaran kurang terjangkau oleh perakaran bawang merah meskipun jumlah yang diberikan sudah sesuai dosis atau bahkan sudah berlebih (Sumiati dan Gunawan 2006), sehingga keberadaan infestasi CMA pada perakaran bawang merah sangat membantu penyerapan unsur hara khususnya unsur P yang dibutuhkan oleh tanaman.…”

“…N0P0, tanpa inokulasi CMA dan tanpa pemupukan N, P, dan K; N0P1, diinokulasi CMA dan tanpa pemupukan N, P, dan K; N0P2, diaplikasi fungisida kimia dan tanpa pemupukan N, P, dan K; N1P0, tanpa inokulasi CMA dan dengan pemupukan N, P, dan K; N1P1, diinokulasi CMA dan dengan pemupukan N, P, dan K; N1P2, diaplikasi fungisida kimia dan dengan pemupukan N, P, dan K. kembangan penyakit yang lebih rendah dibandingkan dengan perlakuan lain. Peran CMA terhadap kesehatan tanaman telah banyak diteliti namun perannya dalam pengendalian penyakit yang menginfeksi daun masih dalam tahap penelitian dan menunjukkan hasil yang bervariasi (Gernns et al 2001), tanaman yang diinokulasi CMA cenderung lebih tahan terhadap patogen tipe nekrotrof (Fritz et al 2006;De La Noval et al 2007). Cendawan A. porri penyebab bercak ungu merupakan cendawan yang bersifat nekrotrofik, yaitu cendawan yang hidup dan berkembang pada sisa-sisa tanaman yang mati, dan apabila kondisi tanaman lemah, karena kekurangan unsur hara maupun cekaman lainnya maka dapat menyerang dan menimbulkan kerugian ekonomi (Woudenberg et al 2014).…”