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  • Author or Editor: Carlos F. Quiros x
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Abstract

In husk tomato, Physalis ixocarpa Brot., a wide range of self-incompatibility phenotypes was observed upon self-pollination. Self-incompatibility seems to be a polygenic trait of low heritability, affected by inbreeding depression and by environment. Organ coloration and leaf serration also were found to be polygenic traits. The chromosomes of this species are characterized by conspicuous heterochromatic knobs which would facilitate identification of each pair. Attempts to hybridize P. ixocarpa with P. floridiana L. and P. peruviana L. were unsuccessful. Propagation by cuttings is readily attainable in P. ixocarpa and might be useful for growing and intercrossing field selections in isolation plots.

Open Access

Abstract

An average natural cross pollination (NCP) value of 1.20% was found in tomatoes (Lycopersicon esculentum Mill.) grown in Delaya, Mexico. NCP values at 2 m to 36 m were less than 0.17%, thus 100 m isolation distance might suffice to avoid pollen contamination. The pollinator bees found in the area were Augochlorella neglectula Cockerell, Dialictus sp, Exomalopsis mellipes Cresson, and Bombus sonorus say; the last two species were most frequently observed pollinating tomato flowers.

Open Access
Authors: and

DNA samples from 21 cultivars of celery (Apium graveolens L. var. dulce) were subjected to amplified fragment length polymorphism (AFLP) analysis. The most informative adapter combination was EcoRI-TaqI. All cultivars could be distinguished from each other by their unique fingerprints based on 73 markers. The program NTSYS grouped the cultivars in three main clusters according to their origin. The groupings observed agreed, with a few exceptions, with those expected by historical accounts and previous analyses based on biochemical and ramdomly amplified polymorphic DNA (RAPD) markers.

Free access

Abstract

A technique for collection and storage of viable celery (Apium graveolens L.) pollen is reported for the cv. Tall Utah 52-70R and the annual strain A143. Umbels at anthesis were dried in an incubator for 14 hr at 31°C, crushed by hand, and passed through a sieve. The pollen released by this operation was collected on a sheet of paper and stored in gelatin capsules. High drying temperatures were detrimental to pollen viability. Pollen collection at different times of the day did not affect viability. After 6 days at 24°, a significant percentage of pollen grains was still viable. The viability declined close to 0% in 9 to 12 days. Pollen of A143 survived better than that of ‘T.U. 52-70R’. Pollen stored for 9 months at 4° maintained a viability of 45% to 50%, but declined close to 0% by the 18th month. Pollen stored at −10° maintained a viability of 10% to 30% by the 18th month. Storage of celery pollen at −10° for 6 to 9 months will keep enough viability for pollinations. Use of stored viable pollen will help with the crossing of celery, as it is often difficult to synchronize the flowering of different plants.

Open Access

Celery cultivars (Apium graveolens var. dulce) in North America have a narrow genetic base. Twenty-two celery, one celeriac and one annual cultivar were screened for polymorphic RAPD (Random Amplified Polymorphic DNA) markers with 28 arbitrary 10-mer primers. Among the total 231 bands obtained, 28 (12%) of the bands were polymorphic among the 24 accessions screened, but only 18 (7.8%) were polymorphic within the 22 celery cultivars. These markers are sufficient to distinguish each of the cultivars used. The average number of marker differences is 6.2 between two celery cultivars, 13.5 between the celeriac and the remaining cultivars, and 16.5 between the annual and the other cultivars. The relationship among the celery cultivars disclosed from this study is basically consistent with that observed using total protein and isozyme markers. RAPD technology provides a new alternative for cultivar identification in celery.

Free access

Phylogenetic relationships of seven Apium species, including three horticultural types of A. graveolens, were assayed for RFLPs using cDNA, chloroplast DNA, and rDNA probes. Most of the probes had been previously mapped in celery. The three horticultural types of A. graveolens were found to be less polymorphic than the wild species and in phylogenetic analysis they clustered together. The wild species formed a cluster on the dendrogram corresponding to their origin in the southern hemisphere. A. nodiflorum, a wild species from Ethiopia formed a branch on the phylogenetic tree apart from all other species. This, along with morphological considerations, suggests that A. nodiflorum should be reclassified outside the genus Apium.

Free access

Morphology and fertility were characterized for 22 intersubspecies hybrids within B. campestris L. Nine subspecies, representing crop types from different geographical areas, were used as pollen donors on three different seed parents. Stability of scored morphological characters was divided into four classes based on their appearance in F1 hybrids; i) constant (present in all hybrids when the character was present in one of the parents, e.g., enlarged hypocotyl, divided leaf), ii) variable (present in some hybrids when the character was present in parent types, e.g., petiole color, pubescence), iii) novel (appearing in hybrids but not present in parents, e.g., anther tip spot, self-compatibility), and iv) reciprocal differences. Constant characters are assumed to have a strong genetic component, variable characters may result from heterozygosity in parents, an allelic series, or polygenic inheritance, and novel characters may arise through mutation or altered gene or physiological interactions. Reciprocal crosses revealed morphological components controlled by the maternal parent, and were most striking in pak-choi (ssp. chinensis) by turnip [ssp. rapifera (Metzg.) Sinsk.] hybrids. Pollen and seed fertility of hybrids was generally reduced when Indian oilseeds [ssp. dichomata (Roxb.) Olsson; ssp. trilecularis (Roxb.) Olsson] were used as parents. Inheritance of the enlarged hypocotyl character was tested in one F2 population. Segregation of the enlarged hypocotyl trait was consistent with a hypothesis of a dominant Mendelian locus. Various novel characters appeared in this F2 population that were not evident in the parents of the hybrid, some of which also showed Mendelian segregation. Genetic differentiation of nuclear or plastid genomes may account for these observations.

Free access

To characterize the celery (Apium graveolens L. var. dulce, 2n = 2x = 22) genome, 126 celery cDNA clones and 340 random 10-mer primers were used to generate restriction fragment-length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) markers between two cultivated types. Different abundance classes of the genomic sequences represented by the cDNA clones and the RAPD markers were observed. Most of the cDNA clones were single-copy sequences, suggesting the true diploid nature of the celery genome. Nearly half of the 39 RAPD markers tested by Southern hybridization were multiple-copy sequences. Of the RAPD markers tested, 28% was single- and low-copy, and 26% was high-copy sequences. The polymorphism level of the cDNA clones was 23% when tested with four restriction enzymes (Eco RI, Eco RV, Hin dIII, and Hae III). A positive association was observed between RFLP level and the size of cDNA inserts or hybridized restriction fragments. Deletion, insertion, and base substitution were important in the formation of the RFLP markers. Eighty-two (23%) of the 340 primers tested yielded useful RAPD markers, but only 3.8% of the amplified products were polymorphic. Base substitution may be the most important mechanism for the RAPD markers in celery. The RAPD fragments revealed no RFLP markers when tested by Southern hybridization, implying that RAPD markers are an important complement to RFLP markers in genomic mapping in celery. Random methylation of cytosine was determined in 5S rDNA on Bam HI and Hin dIII cutting sites that produced ladder patterns characteristic of tandem repeats.

Free access

Abstract

Hybridization in celery is a difficult task faced by the breeder due to the complex floral biology. Celery flowers are hermaphroditic but protandrous and are arranged in compound inflorescences or umbels, formed by small groups of flowers or umbellets disposed in whorls (3). The different developmental stages of the flowers in the umbel makes it difficult to control pollinations effectively. Pollen from young flowers will pollinate old ones that have receptive stigmas in the same inflorescence or anywhere else on the plant. Honma (4) reported a useful technique for celery hybridization, which is the standard procedure used today by breeders. The accuracy of this method depends on the faithful drop of stamens before any of the stigmas become receptive; otherwise, accidental self-pollinations will occur.

Open Access