Available cloned genes and markers for genetic improvement of biotic stress resistance in rice.

Biotic stress is one of the major threats to stable rice production. Climate change affects the shifting of pest outbreaks in time and space. Genetic improvement of biotic stress resistance in rice is a cost-effective and environment-friendly way to control diseases and pests compared to other methods such as chemical spraying. Fast deployment of the available and suitable genes/alleles in local elite varieties through marker-assisted selection (MAS) is crucial for stable high-yield rice production. In this review, we focused on consolidating all the available cloned genes/alleles conferring resistance against rice pathogens (virus, bacteria, and fungus) and insect pests, the corresponding donor materials, and the DNA markers linked to the identified genes. To date, 48 genes (independent loci) have been cloned for only major biotic stresses: seven genes for brown planthopper (BPH), 23 for blast, 13 for bacterial blight, and five for viruses. Physical locations of the 48 genes were graphically mapped on the 12 rice chromosomes so that breeders can easily find the locations of the target genes and distances among all the biotic stress resistance genes and any other target trait genes. For efficient use of the cloned genes, we collected all the publically available DNA markers (~500 markers) linked to the identified genes. In case of no available cloned genes yet for the other biotic stresses, we provided brief information such as donor germplasm, quantitative trait loci (QTLs), and the related papers. All the information described in this review can contribute to the fast genetic improvement of biotic stress resistance in rice for stable high-yield rice production.

First report of root-knot nematode, Meloidogyne arenaria, on lavender in Turkey.

Lavender is a medicinal and aromatic plant that is widely grown in Turkey. Gall symptoms were observed on roots of lavender (Lavandula angustifolia Mill.) collected from Kirklareli and Edirne provinces. Egg masses were collected from galled roots. DNA isolated from all samples was screened by species-specific primers belonging to the most common species of root-knot nematodes and M. arenaria was the only species that was identified in all of the samples analyzed. This is the first report of M. arenaria infecting lavender in Turkey.Lavender is a medicinal and aromatic plant that is widely grown in Turkey. Gall symptoms were observed on roots of lavender (Lavandula angustifolia Mill.) collected from Kirklareli and Edirne provinces. Egg masses were collected from galled roots. DNA isolated from all samples was screened by species-specific primers belonging to the most common species of root-knot nematodes and M. arenaria was the only species that was identified in all of the samples analyzed. This is the first report of M. arenaria infecting lavender in Turkey.