Identification of molecular markers associated with mite resistance in coconut (Cocos nucifera L.)

An Intimate Relationship Between Eriophyoid Mites and Their Host Plants - A Review

Eriophyoid mites (Acari Eriophyoidea) are phytophagous arthropods forming intimate relationships with their host plants. These mites are associated with annual and perennial plants including ferns, and are highly specialized with a dominant monophagy. They can be classified in different ecological classes, i.e., vagrant, gall-making and refuge-seeking species. Many of them are major pests and some of them are vectors of plant pathogens. This paper critically reviews the knowledge on eriophyoids of agricultural importance with emphasis on sources for host plant resistance to these mites. The role of species belonging to the family Eriophyidae as vectors of plant viruses is discussed. Eriophyoid-host plant interactions, the susceptibility within selected crops and main host plant tolerance/resistance mechanisms are discussed. Fundamental concepts, subjects, and problems emerged in this review are pointed out and studies are suggested to clarify some controversial points.

Advances in improvement of quality and resistance in a multipurpose crop: sea buckthorn

Sea buckthorn is a berry crop with multiple uses. The berries are highly appreciated for their unique taste but are also very rich in bioactive compounds with powerful nutritional and medicinal values. In addition, the plants grow well under adverse conditions, and are often used to fight soil erosion. Utilization of sea buckthorn has therefore increased around the world but serious problems have, nevertheless, been encountered due to drought, salinity, diseases and insect pests. This review covers important aspects of sea buckthorn research, such as heritable and environmentally induced variation in biochemical compounds, causes and effects of the devastating dried-shrink disease, susceptibility to insect pests, methods for conventional breeding, and the utilization of DNA markers for taxonomical and population genetic analyses, and for investigating the inheritance of quality and resistance traits. We also present possibilities to implement innovative biotechnological breeding methods, especially metabolite profiling and MAS/GRC-based markers, for fast and efficient development of elite genotypes with specific nutritional- and health-related bioactive compounds and strong resistance to biotic and abiotic stress.

Metabolomics: creating new potentials for unraveling the mechanisms in response to salt and drought stress and for the biotechnological improvement of xero-halophytes

Breeders have long been interested in understanding the biological function and mechanism of xero-halophytes and their ability for growth in drought-stricken and salinized environments. However, the mechanisms in response to stress have been difficult to unravel because their defenses require regulatory changes to the activation of multiple genes and pathways. Metabolomics is becoming a key tool in comprehensively understanding the cellular response to abiotic stress and represents an important addition to the tools currently employed in genomics-assisted selection for plant improvement. In this review, we highlight the applications of plant metabolomics in characterizing metabolic responses to salt and drought stress, and identifying metabolic quantitative trait loci (QTLs). We also discuss the potential of metabolomics as a tool to unravel stress response mechanisms, and as a viable option for the biotechnological improvement of xero-halophytes when no other genetic information such as linkage maps and QTLs are available, by combining with germplasm-regression-combined marker-trait association identification.

What's "cool" on eriophyoid mites?

Fundamental knowledge on the morphology, biology, ecology, and economic importance of Eriophyoidea has been exhaustively compiled by Lindquist et al. (Eriophyoid mites--their biology, natural enemies and control; Elsevier, 1996). Since that time, the number of recognized species and the economic importance of the taxon have increased substantially. The aim of this paper is to analyze and briefly review new findings from eriophyoid mites' literature after Lindquist et al. book, stressing persistent gaps and needs. Much recent attention has been given to sampling and detection, taxonomy and systematics, faunistic surveys, internal morphology, rearing techniques, biological and ecological aspects, biomolecular studies, and virus vectoring. Recommendations are made for integrating research and promoting broader dissemination of data among specialists and non-specialists.

Associations of SRAP markers with dried-shrink disease resistance in a germplasm collection of sea buckthorn (Hippophae L.)

Sea buckthorn ( Hippophae L.) is a woody, outcrossing dioecious pioneer plant, being widely planted as a new berry crop with rich nutritional and medicinal compounds. This long-juvenile and long-lived woody plant can be more difficult to cultivate than other crop plants. Dried-shrink disease (DSD) is a dangerous pathogen that destroys sea buckthorn and halts commercial production. We estimated variability of sequence-related amplified polymorphism (SRAP) markers in 77 accessions of 22 sea buckthorn cultivars to seek markers associated with DSD resistance and help to identify potential breeding cultivars. Seventeen SRAP primer combinations generated 289 bands, with a mean of 17 bands per primer combination. At a Dice coefficient of 0.852, the dendrogram generated with 191 polymorphic bands clustered 73 accessions of Hippophae rhamnoides into 2 groups and 4 accessions of Hippophae salicifolia into 1 group. Eleven SRAP markers (Me1-Em3600, Me1-Em1680, Me2-Em1650, Me2-Em1950, Me3-Em61300, Me2-Em6320, Me2-Em6400, Me1-Em2600, Me1-Em11200, Me1-Em11700, Me2-Em2250) were significantly correlated with DSD resistance (P < 0.001). These markers provide a viable option for breeding programs that select lineages with DSD resistance, especially when no other genetic information, such as linkage maps and quantitative trait loci, are available.