Inventory and world geographical distribution of the olive tree (Olea europaea L.) diseases caused by viruses, bacteria and phytoplasma

The objective of this work is to prepare an Inventory about the viral and bacterial diseases of the olive tree (Olea europaea L.) and to study their Geographical distribution in the world. Fifteen viruses were considered as pathogens on the olive tree, these viruses were reported in 22 countries in five continents showing different symptoms on different olive tree varieties. All viruses were reported in Italy, some of these viruses were found only in the Eurepean continent, such as Olive vein yellows associated virus (OVYaV), Olive yellow mottling and decline associated virus (OYMDaV), Olive mild mosaic virus (OMMV) and Olive semilatent virus (OSLV). Two bacteria were reported as pathogen on the olive tree; Pseudomonas savastanoi. pv. savastanoi responsible bacteria of thr olive knot; a serious disease of olive (Olea europaea L.) in the Mediterranean region. This bacteria was detected in 22 countries in five continents, the majority of these countries exist in the Mediterranean Basin. Another bacteria was Xylella fastidiosa responsible of the quick decline syndrome of olive (OQDS), was deteted in Europe in four countries (Italy, Spain, Portugal and Slovenia) and in America in three countries (USA, Argentina and Brazil). Phtoplasmas was reported in 5 countries in three continents (Europe, Asia and Australia)

Mycorrhizae: Diversity and roles in plant ecosystems

Mycorrhizae are fungi that live in association with the roots of plants, thus constituting an essential symbiosis in terrestrial ecosystems. Arbuscular endomycorrhizae, phylum Glomeromycota, are the most widely distributed in all ecosystems. They colonize the roots of the majority of terrestrial plants and provide several ecoservices. They are involved in plant growth, absorption of water and specific mineral elements (phosphorus, nitrogen, copper, zinc, and some vitamins), structural stability of soils, and participate in the resistance to biotic and abiotic stresses. The interaction between phosphate-solubilizing bacteria (PSB) and arbuscular mycorrhizal fungi (AMF) positively influences soil fertility and plant productivity.This review provideS information on previous research carried out in Morocco on mycorrhizal fungi, particularly the endomycorrhizae. Moreover, this review analyzes the positive role that mycorrhizal fungi can play as growth biostimulators and bioprotectors of plant species. Keywords: Morocco, mycorrhizae, diversity, systematic, importanc

Contribution to the inventory of lichens encountered in the reserve of Sidi Boughaba (Morocco)

ABSTRACT A study of the lichen flora encountered in the Sid

Effect of phospho-compost and phosphate laundered sludge combined or not with endomycorrhizal inoculum on the growth and yield of tomato plants under greenhouse conditions

The study aims to evaluate the eff ect of endomycorrhizal inoculum (arbuscular mycorrhizal fungi), phospho-compost and phosphate sludge in single (M, PC, PS) or dual combinations (PC+M, PS+M, PS+PC) compared to agricultural and Mamora soils (A and S) on the growth, fl owering, and yield of tomato plants. Among the studied treatments, the substrates containing 5% of phospho-compost combined with endomycorrhizal inoculum (PC+M) gave the most positive eff ect followed by phospho-compost (PC) and endomycorrhizal inoculum (M). In response to PC+M substrate, tomato plant height, the number of leaves and fl owers attained 90 cm, 30, and 25, respectively. In substrates PC and M, tomato plants showed a height of 85 and 75 cm, leaves number of 30 and 19 leave/plant and number of fl owers of 21, and 19 fl ower/plant. An optimal yield with (12 fruits/plant) was recorded in tomato plants grown on the substrate amended with bio-inoculant (AMF) and phospho-compost at a rate of 5%. In terms of qualitative parameters, the highest fresh and dry weight of aerial plant parts and root system were recorded in tomato plants grown in culture substrate incorporating 10 g of endomycorrhizal inoculum and 5% of phospho-compost reaching respectively103.4 g, 34 g 90.1 g, 28.9 g as compared to 87, 51, 23 and 24.1 g noted by tomato plants on the substrate with phospho-compost (5%) (PC). The highest mycorrhization parameters (frequency (F), intensity of mycorrhization (M), average arbuscular content (A), average vesicular content (V), average intraradicular spore content (S)) were found in the roots of tomato plants growing on substrates amended with 5% phospho-compost plus 10 g of endomycorrhizal inoculum, with percentages of 100% F, 61% M, 40.67% A, 18.36% V, and 56.9% S

Diversity of arbuscular mycorrhizal fungi in the rhizosphere of saffron (Crocus sativus) plants along with age of plantation in Taliouine region in Morocco

Saffron cultivation is a viable alternative for marginal areas where low soil fertility and water availability severely limit the cultivation of other crops with higher water and input requirments. Under these conditions, arbuscular mycorrhizal fungi (AMF) are an essential alternative for maintaining fertility and water conservation, stimulating growth, and providing plant protection against soil-borne diseases. The aim of this work is to highlight the diversity of the arbuscular mycorrhizal fungi communities associated with saffron roots in plantations of different ages (two, four and ten years old) in the region of Taliouine (Morocco). The highest number of endomycorrhizal spores was recorded in the rhizosphere of saffron plants harvested at the level of plots that have carried saffron for two years (138.66/100 g soil), while the lowest number was observed in the rhizosphere of plants of plots that are occupied for 10 years by saffron. All collected spores from plots under study represent 17 morphotypes belonging to 5 genera: Glomus (7 species), Acaulospora (7 species), Rhizophagus (one species), Densicitata (one species), and Funneliformis (one species)

Effects of a Composite Endomycorrhizal Inoculum on Olive Cuttings under the Greenhouse Conditions

This study was carried out in a nursery to evaluate the impact of mycorrhizal fungi on the cutting's root growth, and root colonization of a Moroccan olive variety ‘Picholine Marocaine' under greenhouse conditions during 2 years of cultivation. The results revealed that the inoculation with a composite inoculum of arbuscular mycorrhizal fungi (AMF) stimulated an early root formation and high development of vegetative shoots in inoculated cuttings respectively, 35 days (50 days in the control plots) and 40 days (60 days in the control plots) after their culture. The progressive establishment of mycorrhizal symbiosis in the roots of the inoculated plants showed that the root and vegetative masses were respectively 24 g and 19.5 g two years after inoculation. The average height and the leave's number of the inoculated plants relative to the control were respectively s 42/ 12 cm and 145/12. The newly formed roots were mycorrhizal and present different structures characteristic of AMF: arbuscules, vesicles, hyphae and spores, whose frequency and intensity reached 90% and 75% two years after cuttings cultivation. The arbuscular and vesicular contents and the number of spores were 67%, 96% and 212 spores/ 100 g of soil respectively. The fourteen species of mycorrhizal fungi isolated from the rhizosphere belong to 4 genera (Glomus, Acaulospora, Gigaspora, and Scutellospora) and three families (Glomaceae, Acaulosporaceae and Gigasporacea).The Glomus genus was the most dominant (65%) followed by the Gigaspora genus (22%). Glomus intraradices, Gigaspora sp.2, Glomus versiformes are the most abundant species, their frequency of occurrence are respectively 30%, 21% and 16%

Diversity of Arbuscular Mycorrhizal Fungi in the Rhizosphere of <em>Argania spinosa</em> in Morocco

Despite the importance of arbuscular mycorrhizal fungi (AMF) within forest and agroecosystems, few data are available about how AMF communities are structured in the root zone of the argan tree. Some studies have characterized endomycorrhizal fungi population occurring in rhizosphere soils of argan trees grown in southwest of Morocco, numerous sites in this area harbored unexplored communities. The endomycorrhizae diversity of rhizosphere soils collected from 15 argan forest stands located in Lakhssas, Smimou, Ait Baha, Tamanar, Essaouira, Taroudant (Elkodya), Irherm, Guelmim, Imsouane, Anzi, Tiznit, Taghazoute, Ait Melloul, Bouizakarne, and Oulad Teima have revealed the presence of different AMF communities sharing some species but dissimilar AMF community compositions are noted according to sampling time and site. Additionally, the diverse AMF structures detected such as vesicles, arbuscules and hyphae reflect implicitly the germination of AMF propagules in the rhizospheric area of the Argan tree. The pre-evaluation of AMF in the soil through spores’ density can indicate AMF community dynamics, signaling either the adaptability of mycorrhizal symbionts to the local conditions or its decline. In total, 39 morphotypes of endomycorrhizal fungal spores were identified and described, representing seven genera: Glomus (15 species), Scutellospora (3 species), Entrophospora (4 species), Pacispora (2 species), Gigaspora (4 species), Acaulospora (10 species), and Ambispora (1 species). The genus Glomus has a wide occurrence and had the largest number of species. This chapter gives a great overview of the mycorrhizal status of argan trees in their natural habitats of the main Moroccan argan forests

Effect of the Arbuscular Mycorrhizal Fungi on the Growth and Root Development of Selected Plant Species Suggested for Slope Revegetation

ABSTRAC

Diversity of the olive tree (Olea europaea L.) genetic resources in the region of Ouazzane (North of Morocco): characterization by using the morphological descriptors I IN NT TE ER RN NA AT TI IO ON NA AL L J JO OU UR RN NA AL L O OF F P PU UR RE E &amp; &amp; A

ABSTRAC