Draft Genomes of Amaranthus tuberculatus, Amaranthus hybridus, and Amaranthus palmeri.

Amaranthus tuberculatus, Amaranthus hybridus, and Amaranthus palmeri are agronomically important weed species. Here, we present the most contiguous draft assemblies of these three species to date. We utilized a combination of Pacific Biosciences long-read sequencing and chromatin contact mapping information to assemble and order sequences of A.

A mosaic monoploid reference sequence for the highly complex genome of sugarcane.

Sugarcane (Saccharum spp.) is a major crop for sugar and bioenergy production. Its highly polyploid, aneuploid, heterozygous, and interspecific genome poses major challenges for producing a reference sequence.

Molecular markers reliably predict post-harvest deterioration of fresh-cut lettuce in modified atmosphere packaging.

Fresh-cut lettuce is popular, but highly perishable product. Genetic studies of two bi-parental populations derived from crossing parents with rapid and slow rates of deterioration showed that the deterioration rate is a heritable trait (broad spectrum heritability, of 0.56-0.

Resistance to Downy Mildew in Lettuce 'La Brillante' is Conferred by Dm50 Gene and Multiple QTL.

Many cultivars of lettuce (Lactuca sativa L.) are susceptible to downy mildew, a nearly globally ubiquitous disease caused by Bremia lactucae. We previously determined that Batavia type cultivar 'La Brillante' has a high level of field resistance to the disease in California.

The inheritance of resistance to bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in three lettuce cultivars.

Lettuce yields can be reduced by the disease bacterial leaf spot (BLS) caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) and host resistance is the most feasible method to reduce disease losses. The cultivars La Brillante, Pavane and Little Gem express an incompatible host-pathogen interaction as a hypersensitive response (HR) to California strains of Xcv resulting in resistance.

Identification of QTLs conferring resistance to downy mildew in legacy cultivars of lettuce.

Many cultivars of lettuce (Lactuca sativa L.), the most popular leafy vegetable, are susceptible to downy mildew disease caused by Bremia lactucae. Cultivars Iceberg and Grand Rapids that were released in the 18th and 19th centuries, respectively, have high levels of quantitative resistance to downy mildew.

A high-density, integrated genetic linkage map of lettuce (Lactuca spp.).

An integrated map for lettuce comprising of 2,744 markers was developed from seven intra- and inter-specific mapping populations. A total of 560 markers that segregated in two or more populations were used to align the individual maps. 2,073 AFLP, 152 RFLP, 130 SSR, and 360 RAPD as well as 29 other markers were assigned to nine chromosomal linkage groups that spanned a total of 1,505 cM and ranged from 136 to 238 cM.

A detailed linkage map of lettuce based on SSAP, AFLP and NBS markers.

Molecular markers based upon a novel lettuce LTR retrotransposon and the nucleotide binding site-leucine-rich repeat (NBS-LRR) family of disease resistance-associated genes have been combined with AFLP markers to generate a 458 locus genetic linkage map for lettuce. A total of 187 retrotransposon-specific SSAP markers, 29 NBS-LRR markers and 242 AFLP markers were mapped in an F(2) population, derived from an interspecific cross between a Lactuca sativa cultivar commonly used in Europe and a wild Lactuca serriola isolate from Northern Europe. The cross has been designed to aid efforts to assess gene flow from cultivated lettuce into the wild in the perspective of genetic modification biosafety.

Towards an expanded and integrated linkage map of cucumber (Cucumis sativus L.).

Linkage maps in cucumber (Cucumis sativus var. sativus L.) have been constructed using morphological traits, isozymes, restriction fragment length polymorphisms (RFLPs), and random amplified polymorphic DNAs (RAPDs).

A genetic map of cucumber composed of RAPDs, RFLPs, AFLPs, and loci conditioning resistance to papaya ringspot and zucchini yellow mosaic viruses.

The watermelon strain of papaya ringspot virus (PRSV-W) and zucchini yellow mosaic virus (ZYMV) are potyviruses that cause significant disease losses in cucumber. Resistances have been identified primarily in exotic germplasm that require transfer to elite cultivated backgrounds. To select more efficiently for virus resistances, we identified molecular markers tightly linked to PRSV-W and ZYMV resistances in cucumber.