Enormous genomic resources have been developed for plants in the monocot order Poales; however, it is not clear how representative the Poales are for the monocots as a whole. The Asparagales are a monophyletic order sister to the lineage carrying the Poales and possess economically important plants such as asparagus, garlic, and onion. To assess the genomic differences between the Asparagales and Poales, we generated 11,008 unique ESTs from a normalized cDNA library of onion. Sequence analyses of these ESTs revealed microsatellite markers, single nucleotide polymorphisms, and homologs of transposable elements. Mean nucleotide similarity between rice and the Asparagales was 78% across coding regions. Expressed sequence and genomic comparisons revealed strong differences between the Asparagales and Poales for codon usage and mean GC content, GC distribution, and relative GC content at each codon position, indicating that genomic characteristics are not uniform across the monocots. The Asparagales were more similar to eudicots than to the Poales for these genomic characteristics.

The Poales (which include the grasses) and Asparagales [which include onion (Allium cepa L.) and other Allium species] are the two most economically important monocot orders. Enormous genomic resources have been developed for the grasses; however, their applicability to other major monocot groups, such as the Asparagales, is unclear. Expressed sequence tags (ESTs) from onion that showed significant similarities (80% similarity over at least 70% of the sequence) to single positions in the rice genome were selected. One hundred new genetic markers developed from these ESTs were added to the intraspecific map derived from the BYG15-23xAC43 segregating family, producing 14 linkage groups encompassing 1,907 cM at LOD 4. Onion linkage groups were assigned to chromosomes using alien addition lines of Allium fistulosum L. carrying single onion chromosomes. Visual comparisons of genetic linkage in onion with physical linkage in rice revealed scant colinearity; however, short regions of colinearity could be identified. Our results demonstrate that the grasses may not be appropriate genomic models for other major monocot groups such as the Asparagales; this will make it necessary to develop genomic resources for these important plants.

Little or no change in ethylene or C02 production occurred in rin tomato mutant fruits monitored for up to 120 days after harvest. Of the abnormally ripening tomatoes investigated, including "Never ripe" (Nr Y a h, Nr c 12 r), "Evergreen" (gf r) and "Green Flesh" (gf), only rin did not show a typical climacteric and ethylene rise.Fruits from F1 plants resulting from reciprocal crosses between rin and normal plants apeared to ripen normally, but when compared to normal fruit, their ripening was delayed as measured by ethylene and C02 production and color change. These fruits produced only one-third to one-half as much ethylene at the peak of production compared to normal fruits.Exogenous ethylene or propylene treatment did not stimulate ethylene production by rin fruits but did stimulate C02 production. The C02 stimulation persisted only in the presence of the exogenous olefins. Stimulation of C02 production could be repeated several times in the same fruit. Wounding stress stimulated both ethylene and C02 production in rin fruits. It was concluded that rin tomato fruits behave like nonclimacteric fruits.catalytically (6,19). Propylene treatment of these fruits stimulates both ethylene production and respiration (19).In climacteric fruits, ethylene is generally considered to be the trigger of the ripening syndrome (21), and its presence at proper levels has been shown to be necessary for normal ripening (7, 16).Normal tomato fruits have been shown to be of the climacteric type (2,8,10, 27,28), and the response of tomato fruits to ethylene treatment has been investigated (15, 22). As in other tissues (1,17,18,26), tomato fruits respond to wounding stress by greatly increased ethylene and CO2 production (20).Reports concerning abnormally ripening tomato mutants have been published (13,14,24). Of special interest is the rin tomato mutant described by Robinson and Tomes (25) as a spontaneous mutation in a breeding line. Fruits of the rin mutant remain green while normal fruits ripen and turn red. The mutant eventually turns a lemon color with little or no lycopene development. Genetic analysis showed that rin was a monogenic recessive determined characteristic with no linkage associations except large sepal size. Little work has been done on the physiology or biochemistry of these ripening mutants (11). The respiratory and ethylene production behavior of the rin tomato mutant is described in this report. MATERIALS AND METHODSBiale (4) 6242.Plants of the F5 generation of rin and the normal breeding line (61-37, Fireball X Cornell 54-149) from which it originated were grown in the greenhouse (15 C night, 20 C day) and trained to a single stem. Flowers were tagged at anthesis with only one flower (lst or 2nd) per cluster being pollinated. All others in a cluster were excised. Fruit load per plant was limited to 8 to 10 fruits. Fruits were harvested 30 days after anthesis, the stems were removed carefully, and fruits were washed in water and dried with paper towels. Fruits of similar size were used for all tr...

Transient expression studies using blueberry leaf explants and monitored by beta-glucuronidase (GUS) assays indicated Agrobacterium tumefaciens strain EHA105 was more effective than LBA4404 or GV3101; and the use of acetosyringone (AS) at 100 microM for inoculation and 6 days co-cultivation was optimum compared to 2, 4, 8, 10 or 12 days. Subsequently, explants of the cultivars Aurora, Bluecrop, Brigitta, and Legacy were inoculated with strain EHA105 containing the binary vector pBISN1 with the neomycin phosphotransferase gene (nptII) and an intron-interrupted GUS gene directed by the chimeric super promoter (Aocs)3AmasPmas. Co-cultivation was for 6 days on modified woody plant medium (WPM) plus 100 microM AS. Explants were then placed on modified WPM supplemented with 1.0 mg l(-1) thidiazuron, 0.5 mg l(-1) alpha-naphthaleneacetic, 10 mg l(-1) kanamycin (Km), and 250 mg l(-1) cefotaxime. Selection for Km-resistant shoots was carried out in the dark for 2 weeks followed by culture in the light at 30 microE m(-2) s(-1) at 25 degrees C. After 12 weeks, selected shoots that were both Km resistant and GUS positive were obtained from 15.3% of the inoculated leaf explants of cultivar Aurora. Sixty-eight independent clones derived from such shoots all tested positive by the polymerase chain reaction using a nptII primer. Eight of eight among these 68 clones tested positive by Southern hybridization using a gusA gene derived probe. The transformation protocol also yielded Km-resistant, GUS-positive shoots that were also PCR positive at frequencies of 5.0% for Bluecrop, 10.0% for Brigitta and 5.6% for Legacy.

Lutein and zeaxanthin are becoming established as carotenoids beneficial for protection against common age-associated eye diseases. Thus, 15 potato (Solanum tuberosum subsp. tuberosum L.) breeding lines, cultivars Atlantic, Spunta, and Yukon Gold; and orange flesh OR-4 were surveyed for carotenoid profiles. Seven carotenoids, including violaxanthin, neoaxanthin, antheraxanthin, lutein, zeaxanthin, β-cryptoaxanthin, and β-carotene, were identified in the 19 genotypes. Violaxanthin and lutein were the prominent carotenoids detected in all genotypes studied. Neoaxanthin and antheraxanthin were found in 26% and 63% of the genotypes, respectively. β-Cryptoaxanthin, zeaxanthin, and β-carotene were found in only 5%, 10%, and 16% of the genotypes, respectively. Lutein varied from 19.8 to 119.0 μg·100 g-1 fresh weight across the 15 white- or yellow-flesh breeding lines. In contrast, zeaxanthin was detected at a low level in only one breeding line and at high level in OR-4. The three cultivars had profiles typical of yellow-flesh potatoes `Spunta' and `Yukon Gold'; while `Atlantic' had a typical white-flesh profile and a trace of zeaxanthin. The carotenoid baseline data established in this study provide information for activities to enhance potato for lutein and zeaxanthin.