Identification of Genetic Markers in Olive Linked to Olive Leaf Spot Resistance and Susceptibility

Abstract

<jats:p>Olive leaf spot is a disease of olive (<jats:italic>Olea europaea</jats:italic> L.) caused by the fungal pathogen, <jats:italic>Spilocea oleaginea</jats:italic> Cast<jats:italic>.</jats:italic> Progeny derived from crosses among susceptible, resistant, and semiresistant parental lines were assessed in the field for 8 years and classified as either resistant or susceptible. DNA from some of the progeny of this segregating population was used to identify molecular markers linked to olive leaf spot disease using the randomly amplified polymorphic DNA (RAPD) technique and bulked segregant analysis (BSA). Two DNA bulks were constructed, each containing 13 progeny showing either resistance or susceptibility for the disease, and screened for polymorphisms using 100 primers. One primer produced two polymorphic bands, one of ≈700 base pairs (bp) from the susceptible bulk and the other of ≈780 bp from the resistant bulk. The 780 bp marker appeared in 70.6% of the segregating progeny and 100% of parents showing resistance to leaf spot disease, while the 700 bp marker appeared in 47.1% of the segregating progeny and 100% of the parents showing susceptibility. These markers can be used as screening tools in olive improvement programs.</jats:p>

Development of a Sequence-tagged Site for the RAPD Marker Linked to Leaf Spot Resistance in Olive

“…Four parents from the breeding program were disease-free over a period of 20 years and were designated resistant. The fifth parent showed occasional slight infection and was designated semiresistant as described in Mekuria et al (2001). These trees were used as female parents in hybridizations with four commercial cultivars that showed different degrees of susceptibility to the disease including semiresistance (Mekuria et al, 2001).…”

“…The fifth parent showed occasional slight infection and was designated semiresistant as described in Mekuria et al (2001). These trees were used as female parents in hybridizations with four commercial cultivars that showed different degrees of susceptibility to the disease including semiresistance (Mekuria et al, 2001). Progeny derived from these crosses were screened for olive leaf spot under field conditions for at least 8 years and designated as either resistant or susceptible.…”

“…DNA samples from the five female parents, the four male parents, and 34 of the progeny were used to identify a RAPD marker linked to leaf spot resistance in olives (Mekuria et al 2001). In the present study the same DNA samples were used to develop an STS marker.…”

“…Using bulk segregant analysis (BSA), a RAPD marker linked to resistance to olive leaf spot disease was identified previously (Mekuria et al, 2001) using DNA from a segregating population obtained from a breeding program in Israel. The present investigation reports development of specific primers to generate an STS linked to leaf spot in olives based on that RAPD marker.…”

Morphological and histochemical investigation of the response of Olea europaea leaves to fungal attack by Spilocaea oleagina

“…The resistance of olive varieties to leaf spot disease has been studied extensively (Antón & Laborda, ; Mekuria et al ., ), but the defence mechanisms involved are not well understood. Plants have evolved different strategies to cope with pathogen attacks and several defence responses have been described, mostly in relation to the so‐called plant innate immune system that has the ability to recognize the presence of potential pathogens and initiate effective defence reactions (Dodds & Rathjen, ).…”