Genome-Wide Association Study Reveals Genomic Region Associated with Mite-Recruitment Phenotypes in the Domesticated Grapevine (Vitis vinifera)

Indirect defenses are plant phenotypes that reduce damage by attracting natural enemies of plant pests and pathogens to leaves. Despite their economic and ecological importance, few studies have investigated the genetic underpinnings of indirect defense phenotypes. Here, we present a genome-wide association study of five phenotypes previously determined to increase populations of beneficial (fungivorous and predacious) mites on grape leaves (genus Vitis): leaf bristles, leaf hairs, and the size, density, and depth of leaf domatia. Using a common garden genetic panel of 399 V. vinifera cultivars, we tested for genetic associations of these phenotypes using previously obtained genotyping data from the Vitis9kSNP array. We found one single nucleotide polymorphism (SNP) significantly associated with domatia density. This SNP (Chr5:1160194) is near two genes of interest: Importin Alpha Isoform 1 (VIT_205s0077g01440), involved in downy mildew resistance, and GATA Transcription Factor 8 (VIT_205s0077g01450), involved in leaf shape development. Our findings are among the first to examine the genomic regions associated with ecologically important plant traits that facilitate interactions with beneficial mites, and suggest promising candidate genes for breeding and genetic editing to increase naturally occurring predator-based defenses in grapevines.

Positive Yield Impact of Predacious Mites in Tea Production Areas of Kenya

Tea agro ecosystems are least disturbed in comparison to other crop systems due to the plant canopy type. A survey on predacious mites’ abundance and impact on leaf yield in different tea production areas was carried out in 2014-2015 in Kenya. Major pest species were the red spider mite Oligonychus coffeae and the yellow thrip, Scirtothrips dorsalis. The red crevice mite, Brevipalpus phoenicis was found in few areas and in low numbers. Predacious mites of Phytoseiidae Family were highest at 5.8 and 6.8 mites per sample during dry and wet seasons, respectively. Phytoseiid abundance during the dry and wet seasons did not differ much within most sample sites. Presence of phytoseiid mites in combination with NPK-fertilizer-high altitude led to the strongest correlation to leaf yield than any other combination variable. High phytoseiid density- high altitude was third with positive impact to yield increase after high altitude combined with NPK-fertilizer. The findings here show contributory positive impact of phytoseiids in tea leaf yield in an agro eco-system.

Особливості структури комплексів фітосеїдних кліщів в рослинних асоціаціях міст

20 species of 10 genera of mites of this family Phytoseiidae were found while studying a species composition on the plants of urban environment Amblyseius andersoni Chant, 1957; Amblyseius rademacheri Dosse, 1958; Neosiulus herbarius Wainstein, 1960; Neoseiulus reductus Wainstein, 1962; Euseius finlandicus, Oudemans, 1915; Kampimodromys aberrans Ouderman, 1930; Dubininellus echinus Wainstein et Arutunjan, 1970; Dubininellus juvenis Wainstein et Arutunjan, 1970; Typhlodromus cotoneastri Wainstein, 1961; Typhlodromus laurae Arutunjan, 1974; Typhloctonus aceri Collyer, 1957; Typhloctonus tiliarum Oudemans, 1930; Paraseiulus incognitus Wainstein et Arutunjan, 1967; Paraseiulus soleiger Ribaga, 1902; Amblydromella (s.str.) caudiglans Scheuten,1959; Amblydromella (s.str.) pirianykae Wainstein, 1972; Amblydromella (s.str.) rhenana Oudemans, 1905; Amblydromella clavata Wainstein, 1972; Amblydromella (Aphanoseius) verrucosa Wainstein, 1972; Galendromus longipilus Nesbitt, 1951. The peculiarities of their spreading in plant associations of Kyiv city, Uman city, Vasylkiv town, Brovary town (Ukraine) which differed from each other by various characteristics (population, area, urbanization degree, etc.) were determined. Total 68 species of plants were examined in the territory of Kyiv city where there were 40 species of trees and shrubs (including 2 types of conifers) and 28 species of herbaceous plants; 16 species of 10 genera of predacious phytoseiid mites were found. 14 species of 8 genera of mites were registered on 25 plant species in the territory of Brovary town (16 species of tree-and-shrub and 9 species of herbaceous plants) in the result of processing of collected materials. 10 species of 7 genera were identified while studying the current state of species diversity of predacious mites of Phytoseiidae family on 26 species of trees and shrubs of green urban plantations within Vasylkiv town. 12 species of 7 genera of Phytoseiidae mites were identified in the result of study of urban plantations in Uman city. Common species at studied areas were the following seven species: A. andersoni, A. rademacheri, E. finlandicus, K. aberrans, T. laurae, T. aceri, T. tiliarum. During the researches the domination index (Di). It was found that spreading of mites was different. Dominant species, subdominant species, subdominant of first order and minor members of species complexes were revealed while analysed the species structure of predacious phytoseiidae mites. E. finlandicus was the dominant in all research plots: Kyiv (Di = 51.63 %), Uman (Di = 60.32 %), Vasylkiv (Di = 15.65 %), Brovary (Di = 33.90 %). K. aberrans (Di = 15.52 %) and E. finlandicus was determined as dominant species n Vasylkiv town. K. aberrans (Di = 2.35 %) and T. aceri (Di = 1.30 %) had the status of subdominant species in research areas. We also have been studied the mite species diversity on the grass and shrubs. We studied the mites on the 93 species of plants where 55 were trees and shrubs (58.9 %) and 38 species were the herbaceous plants (41.1 %).