Sudies for the high oleate:low linoleate seed trait in Spanish market-type peanuts (Arachis hypogaea L.) : inheritance and a search for molecular polymorphism /
Whether peanut is used for oil or nuts, the quality of the product depends on the properties of the oil, which comprises approximately 47% of the seed. Oleic and linoleum acids comprise approximately 80% of the oil content. In currently grown cultivate, the ratio of oleic to linoleum acids (O/L) ran...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1999.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731681191&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Whether peanut is used for oil or nuts, the quality of the product depends on the properties of the oil, which comprises approximately 47% of the seed. Oleic and linoleum acids comprise approximately 80% of the oil content. In currently grown cultivate, the ratio of oleic to linoleum acids (O/L) ranges from <1:1 to 2.5:1. Spanish types usually have O/L ratio near 1:1. The nutritional and quality attributes of peanut oil are significantly improved if the oleic acid levels are increased. The increase of oleic acid is typically measured as an increase in the O/L ratio. Research has revealed a high degree of genetic variability in fatty acid composition for peanut varieties, and if the molecular basis for increased oleic acid accumulation were known, peanut fatty acid composition could be modified in numerous ways. The objectives of this research were (i) to determine the inheritance of the high O/L ratio using Spanish market-type cultivars and (ii) to identify molecular marker polymorphism for the high oleate trait. Six Spanish market-type cultivars (all low O/L) were hybridized to F435-2--2 (F435, high O/L) and F₂ and BC₁F₁ progeny were evaluated for O/L ratio. Segregation in these families at either a 3:1 or 15:1 ratio. These ratios indicate that the parents differed for factor(s) controlling the fatty acid ratios at one and two loci, respectively. In objective 2, []-fatty acid desaturase ([]-Fad), an important enzyme in the conversion of oleic to linoleum acid, was isolated and characterized from low and high O/L ratio genotype, Tamspan 90 (T-90) and F435, respectively. Southern Blots showed 3-4 copies/haploid genome and no major differences in organization between the parental lines. Approximately 3525 bp were isolated from both genotypes, including a genomic walk toward the promoter region. The []-Fad contains one intron, the coding region at the other end, and an open reading frame (ORF) of 1140 bp encoding 379 amino acids. Comparisons of the coding sequences from the high and low oleic acid genotypes indicated several single nucleotide polymorphisms (SNPs). One "A" insertion polymorphism was found at 442 bp and an amino acid change at 448 bp from the start codon. |
|---|---|
| Item Description: | Vita. "Major Subject: Plant Breeding". |
| Physical Description: | xv, 167 leaves ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 106-116). |