Search Results

You are looking at 1 - 10 of 146 items for :

  • "cytogenetics" x
  • Refine by Access: All x
Clear All
Full access

William G. Hembree, Thomas G. Ranney, Brian E. Jackson, and Mark Weathington

, 2006 ). Stewartiae includes the disjunct North American and Asian Stewartia (including evergreen species sometimes classified as Hartia ) ( Prince and Parks, 2001 ). Ploidy and Cytogenetics There is some variation in the base chromosome number among

Free access

Thomas G. Ranney, Connor F. Ryan, Lauren E. Deans, and Nathan P. Lynch

to be 29.3 and 29.2 pg, respectively (determined with flow cytometry). Additional study of cytogenetics of Illicium can clarify various discrepancies and further elucidate chromosome and genome size evolution in this basal angiosperm lineage. After

Free access

Guangxin Liu, Yue Lan, Haoyang Xin, Fengrong Hu, Zhuhua Wu, Jisen Shi, and Mengli Xi

( Lee et al., 2014 ; Sultana et al., 2011 ). However, to our knowledge, no molecular cytogenetic studies have been performed to date in L. rosthornii . The PI banding technique was first described by Hanson et al. (1995) , who used it with bacterial

Free access

Darren H. Touchell, Thomas G. Ranney, Dilip R. Panthee, Ronald J. Gehl, and Alexander Krings

. Further, there has been no characterization of wild collected Arundo from South Asia. Thus, the objective of this study was to evaluate genetic diversity, cytogenetics (ploidy, chromosome numbers, and relative genome sizes) and biomass yields of Arundo

Free access

Jason D. Lattier, Thomas G. Ranney, Paul R. Fantz, and Tony Avent

demonstrated that hybridization between tetraploid L. spicata and diploid Ophiopogon may be occurring naturally in the wild, suggesting new possibilities for breeding between genera in liriopogons. However, breeding systems and cytogenetics of liriopogons

Open access

William G. Hembree, Thomas G. Ranney, Nathan P. Lynch, and Brian E. Jackson

regarding cytogenetics of particular accessions and cultivars constrain the development of informed breeding strategies. The objectives of this study were to validate the identification and determine genome sizes and estimated ploidy of an extensive

Free access

Qin Chen and Hai Y. Li

An improved method is described for the isolation of potato metaphase chromosomes for karyotypic and cytogenetic studies. Root tips from diploid Mexican species, Solanum pinnatisectum (2n = 2x = 24) and tetraploid cultivated S. tuberosum (2n = 4x = 48) were given four different pretreatments. The synthetic pyrethroid, Ambush, was the most stable and effective pretreatment reagent, providing the highest percentage of mitotic chromosomes at metaphase and the best spread of countable chromosomes for cytogenetic studies. Compared with an Ambush pretreatment at concentrations of 100-400 ppm, 1 to 10 ppm Ambush produced more easily distinguished chromosomes, which can be useful for comprehensive observation and karyotype analysis in both 2x and 4x potato species. This improved technique for examining mitotic chromosomes will be helpful in describing karyotypes, characterization of new hybrids, and identifying chromosome structural changes that are important in breeding schemes.

Free access

Mary Eubanks

Free access

M. Ulloa-Godinez, J. N. Corgan, and M. Dunford

Cytogenetic studies were performed on Allium fistulosum, A. cepa. their F1 hybrid, and ten backcross (BC1) progenies [(A. fistulosum × A. cepa) × (A. cepa) 1. In meiosis the F1 hybrid showed 41 percent hetercmorphic bivalent pairing with 10.6 +. 1.8 `chiasmata per cell. Meiocytes were observed with one, two and three bridges and fragments, indicating at least three paracentric inversions. Multivalent associations indicate at least two translocations, one involving the satellite chromosome. The percentage of bivalent pairing, bridges and fragments, and multivalent associations varied in BC1 progenies. The F1 hybrid and all of the BC1 plants were either sterile or had very little seed set. The satellite chromosomes used as cytological markers showed variation in nucleolus position, degree of attachment and number.

Free access

Hamidou F. Sakhanokho and Nurul Islam-Faridi

variety, the cytogenetical behavior of the species must be understood ( Myers and Hill, 1940 ). To that end, the results on chromosome number, nuclear DNA content, genome size, base composition as well as ribosomal RNA gene families that we presented here