This study developed an efficient and reliable system for inducing polyploidy in Anoectochilus formosanus Hayata, a top-grade medicinal orchid. The resulting tetraploid gave a significant enhancement on various agronomic traits, including dry weight, fresh weight, shoot length, root length, leaf width, the size of stoma, and number of chloroplasts per stoma. A reduction of the ratio of length t...

A direct relation between gene dosage and amount of the corresponding protein is generally assumed to exist though it has been investigated in a limited number of cases. Yeasts seem to be an ideal material for this type of investigation as they can be easily obtained in different degrees of ploidy. Macromolecular components of yeast cells in polyploid series have been already determined (OGUR e...

the autotetraploidy was achieved in basil using tip meristem treatment of seedlings with various concentrations of colchicine solution (0, 0.05, 0.1, 0.2, 0.5 and 0.75% (w/v) ph = 6). a significant increase in the essential oil content was observed in tetraploids as they carry the potential of productivity of 69 % more oil over the diploids. a field experiment was conducted to investigate the e...

Different explants from diploid and tetraploid plants of Arabidopsis thaliana ecotype Wilna were cultured in vitro on the same medium in the same conditions. The mode and capacity for regeneration and the ploidy level of regenerants were examined in eight callus lines. The explant responses to in vitro conditions depended on the ploidy level of donor plants and on the type of explant. Callus de...

Theory predicts that occasional sexual reproduction in predominantly parthenogenetic organisms offers all the advantages of obligate sexuality without paying its full costs. However, empirical examples identifying and evaluating the costs and benefits of rare sex are scarce. After reviewing the theoretical perspective on rare sex, we present our findings of potential costs and benefits of occas...

In this study, a new chromosome number for Iranian yarrow (Achillea millefolium L.) accessions was reported. Cytological analyses on four Achillea millefolium accessions, indicated that two accessions were diploids (2n=2x=18) and two tetraploids (2n=4x=36). Cluster analysis based on chromosomal characteristics and karyotype asymmetry, categorized the four accessions separated into two groups. I...

Many cases of intercontinental disjunct distributions of seed plants have been investigated, however few have concerned the continents of Eurasia (mainly Central Asia), Africa, and Australia, especially the xerophytic lineages are lacking. Nitraria (Nitrariaceae) is just one of these xerophytic lineages. Previous Nitraria studies have hypothesized either Africa as the ancient center, with dispe...

Chromosome number and meiotic behavior were evaluated in 36 Brazilian accessions of the grass Paspalum (which had never previously been analyzed) to determinate which accessions might be useful in interspecific hybridizations. The analysis showed that one accession of Paspalum coryphaeum was diploid (2n = 2x = 20) and one accession of Paspalum conspersum hexaploid (2n = 6x = 60), the remaining ...

Groundnut is susceptible to a range of diseases and pests owing to its narrow genetic base. Closely related wild relatives of groundnut are diploid, and crossability between diploid wild relatives and tetraploid cultivated groundnut is difficult. Amphidiploid and autotetraploid groundnuts, which are tetraploids (also called synthetic groundnut), were developed at ICRISAT. Crossability between c...