Reference karyotype and cytomolecular map for loblolly pine (Pinus taeda L.)

Genome ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 241-251 ◽  
Author(s):  
M. Nurul Islam-Faridi ◽  
C. Dana Nelson ◽  
Thomas L. Kubisiak

A reference karyotype is presented for loblolly pine (Pinus taeda L., subgenus Pinus, section Pinus, subsection Australes), based on fluorescent in situ hybridization (FISH), using 18S-28S rDNA, 5S rDNA, and an Arabidopsis-type telomere repeat sequence (A-type TRS). Well separated somatic chromosomes were prepared from colchicine-treated root meristems, using an enzymatic digestion technique. Statistical analyses performed on chromosome-arm lengths, centromeric indices, and interstitial rDNA and telomeric positions were based on observations from 6 well-separated metaphase cells from each of 3 unrelated trees. Statistically, 7 of the 12 loblolly pine chromosomes could be distinguished by their relative lengths. Centromeric indices were unable to distinguish additional chromosomes. However, the position and relative strength of the rDNA and telomeric sites made it possible to uniquely identify all of the chromosomes, providing a reference karyotype for use in comparative genome analyses. A dichotomous key was developed to aid in the identification of loblolly pine chromosomes and their comparison to chromosomes of other Pinus spp. A cytomolecular map was developed using the interstitial 18S-28S rDNA and A-type TRS signals. A total of 54 bins were assigned, ranging from 3 to 5 bins per chromosome. This is the first report of a chromosome-anchored physical map for a conifer that includes a dichotomous key for accurate and consistent identification of the P. taeda chromosomes.

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 321-330 ◽  
Author(s):  
Mitchell M Sewell ◽  
Bradley K Sherman ◽  
David B Neale

Abstract A consensus map for loblolly pine (Pinus taeda L.) was constructed from the integration of linkage data from two unrelated three-generation outbred pedigrees. The progeny segregation data from restriction fragment length polymorphism, random amplified polymorphic DNA, and isozyme genetic markers from each pedigree were recoded to reflect the two independent populations of parental meioses, and genetic maps were constructed to represent each parent. The rate of meiotic recombination was significantly greater for males than females, as was the average estimate of genome length for males {1983.7 cM [Kosambi mapping function (K)]} and females [1339.5 cM(K)]. The integration of individual maps allows for the synthesis of genetic information from independent sources onto a single consensus map and facilitates the consolidation of linkage groups to represent the chromosomes (n = 12) of loblolly pine. The resulting consensus map consists of 357 unique molecular markers and covers ∼1300 cM(K).


2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  

1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop

Abstract Four variations of the fell-and-burn technique, a system developed to produce mixed pine-hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing of felling residual stems, as prescribed by the fell-and-burn technique, may be flexible because winter and spring felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of the first growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods within four growing seasons in burned plots and within six growing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122.


1997 ◽  
Vol 21 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Steven E. McKeand ◽  
Robert P. Crook ◽  
H. Lee Allen

Abstract The lack of rank change in growth characteristics when open-pollinated families of loblolly pine (Pinus taeda L.) are planted on different sites in the Southeast has greatly simplified breeding for superior genotypes. Although family rank does not usually change, genotype by environment interactions (GxE) may be very important in operational deployment of families in regeneration programs. Using data from GxE trials and two site preparation-fertilization-herbicide trials, we estimated the growth that different families should achieve following application of these silvicultural practices. Better performing families tend to be most responsive to site changes (i.e. genetically unstable). Growth responses to silvicultural treatment will be overestimated if only the most responsive families are used in silvicultural research trials. Similarly, genetic gains will be overestimated if gain trials are planted on only the best sites or receive intensive culture. South. J. Appl. For. 21(2):84-89.


BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Mengmeng Lu ◽  
Konstantin V. Krutovsky ◽  
C. Dana Nelson ◽  
Tomasz E. Koralewski ◽  
Thomas D. Byram ◽  
...  

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