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  • Author or Editor: Louise Ferguson x
  • Journal of the American Society for Horticultural Science x
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A genomic DNA library enriched for dinucleotide (CT)n and (CA)n and trinucleotide (CTT)n microsatellite motifs has been developed from `Kerman' pistachio (Pistacia vera L.). The enrichment method based on magnetic or biotin capture of repetitive sequences from restricted genomic DNA revealed an abundance of simple sequence repeats (SSRs) in the pistachio genome which were used for marker development. After an enrichment protocol, about 64% of the clones contained (CT)n repeats while 59% contained (CA)n for CT and CA enriched libraries, respectively. In the (CT)n enriched library, compound sequences were 45% while for (CA)n it was 13.5%. In both dinucleotide enriched libraries, about 80% of the clones having microsatellites have a repeat length in the range of 10 to 30 units. A library enriched for trinucleotide (CTT)n contained <19% of the clones with (CTT)n repeats. Of the clones that contained microsatellites, 62% had sufficient flanking sequence for primer design. An initial set of 25 pairs of primers was designed, out of which 14 pairs amplified cleanly and produced an easily interpretable PCR product in the commercially important American, Iranian, Turkish, and Syrian pistachio cultivars. The efficient DNA extraction method developed for pistachio kernels and shells (roasted and nonroasted) yielded DNA of sufficient quality to use PCR to create DNA fingerprints. In total, 46 alleles were identified by 14 primer pairs and a dendrogram was constructed on the basis of that information. The SSR markers distinguished most of the tested cultivars from their unique DNA fingerprint. An UPGMA cluster analysis placed most of the Iranian samples in one group while the Syrian samples were the most diverse and did not constitute a single distinct group. The maximum number of cultivar specific markers were found in `Kerman'(4), the current industry standard in the United States, and the Syrian cultivar Jalab (5). The technique of using extracted DNA from pistachio kernal or shell coupled with the appropriate marker system developed here, can be used for analyses and measurement of trueness to type.

Free access

Salinity’s many stresses may not kill a relatively salt-tolerant perennial in one season, but they can still deplete or modify nonstructural carbohydrate (NSC) pools. Any change to the quantity or quality of NSC reserves may have detrimental effects on phenology and reproduction, as well as yield, in tree crops. This study integrates salinity’s infringement on the energy margins of pistachio rootstock ‘UCB-1’ (an interspecific hybrid of Pistacia atlantica and P. integerrima) at senescence by measuring sugar and starch pools in wood, bark, and roots after treatment with ≈100 days of moderate to high salinity (50–100 mm NaCl and 10–20 mm CaCl2). Supported by a second experiment using sodium orthovanadate (NaOV) to block active xylem retrieval in the same hybrid pistachio rootstock, we conclude that retrieval of Na+ from xylem sap may allow for the preservation of NSC pools (particularly, starch) in mature xylem tissues by limiting the demand for carbon-based osmoticum (sugars). In contrast, younger growing tissues (bark and fine roots) were found to counteract salinity by degrading carbon-dense starch into osmotically active sugars at the expense of total NSC reserves, suggesting a physiological shift toward protection/isolation from environmentally pervasive but potentially toxic salts in these tissues.

Open Access