Evaluation of Arbuscular Mycorrhizal Fungi Capacity to Alleviate Abiotic Stress of Olive (Olea europaeaL.) Plants at Different Transplant Conditions

Abstract

The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.

Fungos Micorrizicos Arbusculares No Desenvolvimento De Mudas De Oliveira (Olea Europaea L.) Cultivadas No Sul De Minas Gerais

“…De posse dos resultados, pode-se inferir que, além do interesse agronômico, há também interesse econômico e ambiental, uma vez que é possível reduzir o tempo de viveiro das mudas, fazendo com que as mudas inoculadas sejam comercializadas de forma antecipada àquelas cultivadas sem inoculação, além de possibilitarem maior resistência ao transplantio e produção de plantas mais vigorosas (Sidhoum e Fortas, 2013;Bompadre et al, 2014).…”

The Role of Microbial Inoculants on Plant Protection, Growth Stimulation, and Crop Productivity of the Olive Tree (Olea europea L.)

“…Low soil fertility and many abiotic stresses, such as high temperatures and drought enhance this tendency [11]. Several abiotic stresses, especially water stress, are strongly related to the transplantation shock that occurs when olive cuttings or seedlings are transplanted in the field decreasing their survival rate [12]; this failure of the young olive plants to root well forces them to expend additional energetic cost in order to adapt to the new environmental conditions [13]. Meddad-Hamza et al [14] showed that when young olive plants, with low root to shoot ratio, were transplanted into natural soil conditions without fertilizers, there was an abrupt decrease of the mineral uptake by the plant, causing stunted growth and increased plant mortality.…”

PENGGUNAAN RHIZOBIUM DAN MIKORIZA UNTUK PERTUMBUHAN Calliandra calothyrsus UNGGUL

“…Aplikasi mikoriza ini telah dibuktikan dapat meningkatkan kualitas semai dalam hal peningkatan nutrisi, ketahanan terhadap hama dan penyakit serta ketahanan terhadap lingkungan tertekan termasuk kekeringan, ketahanan terhadap logam berat serta perbaikan struktur tanah (Ajeesh et al, 2015;Bompadre et al, 2014;Bücking, Liepold, & Ambilwade, 2012).…”

“…Namun demikian, proses terjadinya infeksi pada akar membutuhkan waktu serta berlangsung cukup kompleks karena melewati tahap perkecambahan spora, perkembangan hypha, pembentukan aprosurium, penetrasi akar, pertumbuhan antar sel, pembentukan arbuskular dan kemudian transfer nutrisi baru bisa terjadi (Ajeesh et al, 2015). Bahkan pada saat awal, tanaman harus menyediakan energi untuk proses kolonisasi mikoriza (Bompadre et al, 2014). Hal ini yang diperkirakan menyebabkan pengaruh yang terjadi pada C. calothyrsus menjadi lebih nyata setelah 4 minggu dan bahkan makin meningkat setelah 8 minggu jika dibandingkan pada saat semai masih berumur 1 minggu, seperti yang ditunjukkan pada karakter jumlah daun.…”

“…Meskipun perlakuan mikoriza diterapkan dengan jumlah yang sama, namun keseragaman penyebarannya disekitar perbedaan kelimpahan akar tidak dapat dijamin, oleh karenanya dapat menjadi penyebab perbedaan waktu proses simbiose atau bahkan jika jarak penyebarannya yang terlalu jauh asosiasi akan terhambat. Keberhasilan asosiasi untuk pembentukan nodul akar dari suatu tanaman sangat ditentukan oleh faktor biotik dan faktor lingkungan (Purwantari & Sutedi, 2005) dan spora serta myselium, yang relatif sangat kecil ukurannya, akan pengaruhi lingkungan akar tempat kolonisasi terjadi (Bompadre et al, 2014). Kolonisasi mikoriza dtunjukkan meningkat dengan pemberian rhizobia (Xie et al, 1995) dan ini sesuai dengan penelitian ini yang menunjukkan bahwa peningkatan jumlah mikoriza semakin meningkatkan nodulasi, sehingga sesuai dengan pengaruh saling melengkapi dan sinergi antara rhizobium dan mikoriza saat diterapkan secara bersamaan (Goss & de Varennes, 2002;Sanginga et al, 1999).…”