Rapid estimation of ploidy levels in in vitro-regenerated interspecific Arachis hybrids and fertile triploids

Abstract

A significant correlation among chromosome number, chloroplast number and pollen grain size was observed using interspecific hybrids (2n = 30, 60), Arachis hypogaea (2n = 40), A. stenosperma (P1338280) (2n = 20), A. batizocoi (PI 468329) (2n = 20) and A. viUosulicarpa Hoehne (PI 336984) (2n = 20), representing four ploidy groups. Both chloroplast number in guard cells and pollen grain size were found to be positively correlated with ploidy, and provided a reliable method to distinguish diploid, triploid, tetraploid and hexaploid plants from each other regardless of their taxonomic backgrounds. These methods in combination with root-tip chromosome counts enabled us to confirm ploidy determinations on all three tissue layers, L1, L2 and L3 (guard cells, microsporocytes and root meristematic cells, respectively), and to detect the chimeric nature of some colchicine-treated tissue culture-derived plants. Screening pollen grains by size and the detection of highly stainable and viable, 30-chromosome pollen grains have enhanced the use of tripIoid hybrids in peanut breeding programs.

Chloroplast number in guard cells as ploidy indicator of in vitro-grown androgenic pepper plantlets

“…Various indirect methods based on stomatal guard cell length, (Borrino & Powell 1988), morphological characters (Pehu et al 1987), cytometric analysis of DNA content (Uijtewaal 1987), and chloroplast number per guard cell pair (Jacobs & Yoder 1989;Singsit & Veilleux 1991;Singsit & Ozias-Akins 1992) have been used to estimate the ploidy status of in vitro regenerated plants.…”

“…Indirect ploidy determinations based on chloroplast number in guard cell pairs (Jacobs & Yoder 1989;Singsit & Veilleux 1991;Singsit & Ozias-Akins 1992) or stomatal guard cell length (Borrino & Powell 1988) have been utilized as a convenient, fast and reliable alternative to actual chromosome counts in many crop species. However, when many plants are to be analyzed, this is a rather laborious method.…”

Reaction of Flax (Linum Usitatissimum L.) Calli Culture to Supplement of Medium by Carbon Nanoparticles

“…Poliploidy, aneuploidy and chromosome aberrations in somatic plant and animal cells cultivated in vitro have been observed (Sacristán, 1971). Ploidy variations have been reported for different plants, including both regenerated and transgenic tomato (Ellul et al, 2003), in vitro regenerated Arachis hybrids (Singsit and Ozias-Akins, 1992), somatic hybrids and in vitro propagated potato (Uijtewaal, 1987;Chaput et al, 1990), sugar cane, tobacco (Larkin and Scowcroft, 1981), rice (Chen, 1977), Brassica (Keller et al, 1975), pear (Kadota and Niimi, 2002), strawberry (Hao et al, 2002) and many others. The use of flow cytometry for the measurement of nuclear DNA content, which is based on the use of DNA-specific fluorochromes and on the analysis of the relative fluorescence intensity of stained nuclei (Doleþel, 1991), has been considered as a fast and reliable method (Doleþel et al, 1989).…”

Peanut improvement: production of fertile hybrids and backcross progeny between Arachis hypogaea and A. kretschmeri

“…The ploidy of the derivatives was determined by pollen diameter analysis (Singsit and Ozias-Akins 1992). Three classes were observed: that of the diploid species, A. kretschmeri, was 25 to 27 μm; that of A. hypogaea (tetraploid species) was 45 to 47 μm and that of triploid interspecific derivatives was 27 to 29 μm.…”