Microprojectile bombardment was used to introduce DNA into embryogenic callus of garlic (Allium sativum L.) and produce stably transformed garlic plants. Embryogenic calluses, derived from garlic cultivar `GT96-1', were bombarded with plasmid DNA containing genes coding for hygromycin phosphotransferase and β-glucuronidase. Putatively transformed calluses were identified in the bombarded tissue after 4 months of selection on 20 mg·L-1 hygromycin B. The transgenic nature of the selected material was demonstrated by GUS histochemical assay and Southern blot hybridization analysis, and twenty transgenic plants were regenerated.
Alejandrina Robledo-Paz, José Luis Cabrera-Ponce, Víctor Manuel Villalobos-Arámbula, Luis Herrera-Estrella, and Alba Estela Jofre-Garfias
Job Teixeira de Oliveira, Rubens Alves de Oliveira, Lucas Allan Almeida Oliveira, Paulo Teodoro, and Rafael Montanari
Garlic ( Allium sativum L.) is grown in practically the entire national territory and is recognized as an excellent source of proteins, vitamins, minerals, and fibers that nourish and reduce the incidence of diseases, besides being a food component
M. Al-Zahim, H.J. Newbury, and B.V. Ford-Lloyd
RAPD analysis was employed to assess genetic variation in named cultivars of garlic (Allium sativum L.), and to examine the relationships between cultivated garlic varieties and the wild progenitor Allium longicuspis. Twenty-seven accessions were subjected to RAPD analysis using 26 oligonucleotide primers. Of a total of 292 bands, 63 (21%) were polymorphic. Cluster analysis revealed groupings that in part reflected patterns of morphological variation. All bolting forms (including wild and cultivated) grouped separately from the nonbolting cultivars. A. longicuspis and var. ophioscorodon grouped together, indicating close taxonomic affinity. Based upon relative levels of variation within different groups, we suggest potential relationships within the A. sativum/A. longicuspis complex.
Nilvane T.G. Müller, Gerson R. de L. Fortes, Gioconda C. Nascimento, and Julio Daniels
Garlic (Allium sativum L.) belongs to the Alliaceae family and originated from Asia and Mediterranean countries. Their bulblets are rich in starch and aromatic substances. The rate of garlic propagation in field conditions takes several years for the production of a certain number of seed bulbs for the release of a new variety. The use of tissue culture techniques is a useful tool for overcoming this problem. The aim of this work was to increase the mean number of shoots derived from the meristem isolation and to verify the percentage of callus formation and to analyze vigor of the material. The initial meristems were inoculated in a salt and vitamin B5 media except for the iron element, which was provided by MS medium added to in mg·L-1: myo-inositol (100.0), nicotinic acid (1.0), piridoxine (1.0), thiamine (10.0), sucrose (20.0 g·L-1), agar (6.0 g·L-1). BAP and TDZ were added at: 0.0; 1.0; 1.5; 2.0; and 2.5 μM This material remained in a growth room for a 16-h photoperiod, radiation of 20 μMol·m-2·s-1 and 25 °C for 40 days. Although `Sao Marcos' produced more vigorous shoots, no significant difference was found for the mean number of shoots. `Sao Valentim' cultivar shows more callus at the shoot base, making this cultivar more prone to somaclonal variation On the other hand, BAP estimulates the appearance of callus, but it has been shown that this is cultivar-dependent.
Yayeh Zewdie, Michael J. Havey, James P. Prince, and Maria M. Jenderek*
Garlic has been propagated exclusively by asexual means since time immemorial. The recent discovery of male fertile garlic accessions allowed studies on genetics and garlic improvement. Single nucleotide polymorphism (SNP) and random amplified polymorphic DNA (RAPD) based genetic linkage map was developed for garlic using a segregating population derived from one plant of PI 540316. Progenies segregated for male fertility and other morphological characters. Distortion of segregation was observed for most of the markers. This was expected due to the segregation of recessive deleterious alleles present in the garlic genome. The map contained 23 loci distributed on five linkage groups. It covered 319 cM with the average of 18 cM between loci. Linkage with the male fertility (Mf) locus was established with SNP marker AOB155 (26.7 cM).
M.R. Pooler and P.W. Simon
The effects of cold storage, photoperiod, and growth temperature on flowering incidence in four clones of garlic (Allium sativum L.) were studied. While flowering percentage was influenced most by clone, interactions with photoperiod, growth temperature, and storage occurred. Clone R81 flowered equally well in all conditions, whereas flowering percentage of clones D129, D130, and PI485592 was reduced by cold (4C) storage of either bulbs or plants, long (16-h) photoperiod, and at 18C relative to 10C. The highest flowering percentage in all garlic clones was achieved by growing plants at 10C under short (9- to 10-h) photoperiod with no cold storage of bulbs before planting.
M.M. Jenderek, K.A. Schierenbeck, and R.M. Hannan
Maintenance of garlic (A. sativum L.) germplasm collections is based on year-to-year vegetative propagation of individual accessions. Several accessions are phenotypically similar, often originating from the same region of the world, but have been collected by different people at different times. These accessions are currently maintained as separate and unique samples, but may represent genetic duplication in the collection. In order to identify genetic duplication in the USDA collection, 45 garlic Plant Introduction accessions from the garlic USDA germplasm collection were analyzed for RAPD marker polymorphism. The samples originated from 20 countries worldwide. RAPD bands were generated by 20 decamer primers, using 100-ng DNA template, and 38 PCR amplification cycles. Polymorphism between accessions was defined as presence or absence of particular bands at given loci. However, a few distinguishing RAPD markers were established for selected accessions, identifying additional molecular markers to wholly assess the similarities or polymorphism of the garlic collection units is necessary.
Sun-Tay Choi, Ro-Na Bae*, Dae-Sung Chung, and Seung-Koo Lee
To investigate quality changes of garlic associated with cultivars and storage conditions, northern type `Seosan' and sub-tropical type `Daeseo' garlics were stored at controlled atmosphere (O2 3%, CO2 5%, -1 ± 1°C) condition, low temperature (-1 ± 1°C), and room temperature (20 ± 5°C). The rate of sprouting, weight loss, enzymatic pyruvic acid content, and degree of greening in crushed garlic were determined during storage. The rate of sprouting was higher in `Daeseo' than in `Seosan' garlic in all storage conditions. Sprouting was effectively suppressed in low temperature and controlled atmosphere storage. Weight loss in `Daeseo' garlic was higher than in `Seosan' garlic. Enzymatic pyruvic acid (EP) contents increased for 3 months storage period, and then decreased gradually as the storage period was prolonged at room or low temperatures. However, EP content decreased dramatically during storage under CA condition in both cultivars. When garlic bulbs were crushed, greening appeared in the garlic stored at low temperature for more than one month. However, greening did not occur in the crushed garlic bulbs stored in CA condition.
J. Michele Myers and Philipp W. Simon
Garlic callus derived from young basal plate explants of one genotype was evaluated for regeneration. Callus was initiated on a modified B5 medium supplemented with 2.4-D for 10 weeks and then subcultured on medium with picloram + 2iP for 10 weeks. This friable callus was used in regenerating plants. Callus was transferred to a modified B5 medium with 10 hormonal combinations of auxins and cytokinins in a complete factorial design. Four pieces of callus about 1.0 cm square were transferred to a petri plate with four replications per treatment Callus was subcultured monthly to ensure optimum growth and data was collected after three months in culture. The best regeneration frequency occurred on medium supplemented with picloram + BA. Regenerated lines were then transferred to medium with no hormones for evaluation of single plants. The genetic stability of these regenerated lines was tested using polyacrlyamind gel elcctrophoresis (PAGE) and six isozyme systems. This regeneration system will be very useful in the production of regenerated putative transformed lines from callus.
Jorge Arboleya, Claudio Garcia, and Carlos Suarez
National Research Inst. of Agriculture of Uruguay defined garlic as an important crop because its potential for exportation. Plant population and N management have been studied since 1992. Plant population of 112, 250, 333 and 500 thousand plants/ha at rates of N at 0, 75, 150 and 225 kg·ha–1 were tested in 1992, 1993, and 1995. Drip irrigation and plastic mulch with populations from 240 to 960 thousand plants/ha in 1992 and from 236 to 586 plants/ha in 1993 were evaluated. Nitrogen rates of 0, 40, 80 and 120 kg/ha, and application times were also tested with a population of 250 thousand plants/ha, in 1992 and 1993. Plant population of 240, 320 and 560 thousand plants/ha yielded 12,0; 12,4 and 14,2 t·ha–1 respectively. As plant population increased, bulb size decreased. Yield increased up to rate of N at 150 kg·ha–1.