Effect of N on yield and chemical profile of winter canola in Mississippi.

There is increased interest in winter canola as an oilseeds crop for production of oil or biodiesel in the southeastern United States, but research has been limited. The objective of this study was to evaluate the effect of N (0, 60, 120, 180 kg N ha⁻¹) on productivity, oil content and oil composition of winter canola grown for two cropping seasons at three locations in Mississippi (Stoneville, and two locations at Verona: Verona upland silt loam, Verona-SL and Verona upland clay, Verona-C). Overall, increasing N application rates resulted in corresponding stepwise increase in seed yields in the two locations at Verona, whereas yields in the 60 and 120 kg N ha⁻¹ at Stoneville were not different from each other.

Molecular mapping of the Pl(16) downy mildew resistance gene from HA-R4 to facilitate marker-assisted selection in sunflower.

The major genes controlling sunflower downy mildew resistance have been designated as Pl genes. Ten of the more than 20 Pl genes reported have been mapped. In this study, we report the molecular mapping of gene Pl(16) in a sunflower downy mildew differential line, HA-R4.

Identification of resistance to new virulent races of rust in sunflowers and validation of DNA markers in the gene pool.

Sunflower rust, caused by Puccinia helianthi, is a prevalent disease in many countries throughout the world. The U.S.

Genetic characterization and molecular mapping of a chlorophyll deficiency gene in sunflower (Helianthus annuus).

A major gene controlling chlorophyll deficiency (phenotyped by yellow leaf color, yl) in sunflower was identified and mapped in an F(2) population derived from a cross between two breeding lines. Greenness degree was scored by a hand-held chlorophyll meter in the F(2) population. Leaf tissue from the parents, F(1) hybrids, and some F(2) progenies were also sampled to determine the chlorophyll content.

Mapping one of the 2 genes controlling lemon ray flower color in sunflower (Helianthus annuus L.).

In an F2 population of 120 plants derived from a cross between 2 breeding lines with yellow ray flowers, we observed 111 plants with yellow-colored and 9 plants with lemon-colored ray flowers. The segregation pattern fits a 15:1 (chi2(15:1) = 0.32, P > 0.

Molecular mapping of a nuclear male-sterility gene in sunflower (Helianthus annuus L.) using TRAP and SSR markers.

A nuclear male-sterile mutant, NMS 360, induced by streptomycin from an inbred maintainer line HA 89, possesses a single recessive gene, ms9, controlling male sterility. The present study identified DNA markers linked to the ms9 gene in an F2 population derived from the cross of NMS 360 x RHA 271 and maps the ms9 gene to an existing sunflower SSR linkage map. Bulked segregant analysis was performed using the target region amplification polymorphism (TRAP) marker technique and the simple sequence repeats (SSR) technique.

Construction of BAC and BIBAC libraries from sunflower and identification of linkage group-specific clones by overgo hybridization.

Complementary BAC and BIBAC libraries were constructed from nuclear DNA of sunflower cultivar HA 89. The BAC library, constructed with BamHI in the pECBAC1 vector, contains 107,136 clones and has an average insert size of 140 kb. The BIBAC library was constructed with HindIII in the plant-transformation-competent binary vector pCLD04541 and contains 84,864 clones, with an average insert size of 137 kb.

Characterization of a new Bacillus thuringiensis isolate highly active against Cochylis hospes.

A new bacterial isolate, 00-50-5, from sunflower head extracts was identified as Bacillus thuringiensis (Bt) according to its morphology. Bt isolate 00-50-5 was highly active against the banded sunflower moth (BSM), Cochylis hospes Walsingham. A sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) 4-15% gradient gel of whole strain protein of 00-50-5 revealed six proteins with molecular masses (Mr) of 133, 80, 60, 27, 15, and 14 kDa.

Differences in the fatty acid composition of larvae and metamorphosing sea lampreys, Petromyzon marinus.

This study was designed to evaluate biochemical changes in the fatty acid (FA) compositions of selected lipid depot (kidney and liver) and absorption (intestine) organs in larvae and metamorphosing sea lamprey, Petromyzon marinus. Palmitic or stearic acids were generally the predominant saturated fatty acids (SFA) before and during metamorphosis, but the greatest proportion of myristic acid occurred in renal triacylglycerol (TG). Monoenes, dienes, and polyenes consist mainly of 16:1, 18:1, and 20:1, 18:2 and 20:2omega6, and 18:4omega3, respectively.