The taxonomy and genetics of Picea rubens and its relationship to Picea mariana

1976 ◽  
Vol 54 (9) ◽  
pp. 781-813 ◽  
Author(s):  
Alan G. Gordon
Keyword(s):  
Picea Mariana ◽  
Introgressive Hybridization ◽  
Picea Rubens ◽  
Interspecific Crosses ◽  
Parent Species ◽  
Hybrid Swarm ◽  
Discrete Variation ◽  
Representative Sampling ◽  
Homeostatic Process ◽  
Ecological Barriers

A range-wide sampling of Picea rubens Sarg. populations with a representative sampling of Picea mariana (Mill.) B.S.P. was made to investigate the variation within P. rubens and the nature and extent of hybridization between the two species. Factor analysis using 14, 21, and 24 characters, successively, indicated that the clusters of the parent species were quite discrete. Variation was found to be continuous within but not between the species, and gene flow was not more in one direction than the other. Species were found to maintain their centroides with a very low level of hybridization, and introgressive hybridization was found to be of a very limited nature.Controlled crosses indicated that the crossability of the parent species with the distantly allopatric Picea omorika ranged from 36 to 71%, while the crossability of the sympatric P. rubens × P. mariana and the reciprocal was from 1 to 3%. Other interspecific crosses were considered. Variation in the P. rubens × P. mariana F1 was substantial and sufficient to explain most of the variation observed in the occasional hybrid swarm found in nature. Backcrossing data indicate that it is not more successful than parent species crosses. Regeneration data from a soil site moisture catena for both species were evaluated to estimate the number of hybrids moving into the population relative to the parent species. These were found to be very low. A homeostatic process involving an array of both genetic and ecological barriers is proposed to explain the persistence of P. rubens in the presence of P. mariana and other selection pressures. A comparison is made of the relationships between P. glauca and P. engelmannii and that of P. rubens and P. mariana. It is concluded that the latter are not a species pair in the same sense as the former.

THE CHROMOSOMAL BASIS OF VIABILITY IN INTERSPECIFIC HYBRIDS BETWEEN DROSOPHILA ARIZONENSIS AND DROSOPHILA MOJAVENSIS

1981 ◽  
Vol 23 (1) ◽  
pp. 65-72 ◽  
Author(s):  
E. Zouros
Keyword(s):  
Hybrid Sterility ◽  
Introgressive Hybridization ◽  
Backcross Progeny ◽  
Interspecific Crosses ◽  
Drosophila Mojavensis ◽  
Pure Species ◽  
Ecological Barriers ◽  
Chromosomal Identification ◽  
Interspecific Crossing

The chromosomal effects on differences in viability among progeny from interspecific crosses was studied in the interfertile pair Drosophila arizonensis and Drosophila mojavensis. Interspecific crossing-over was avoided by crossing hybrid males to pure-species females, and chromosomal identification in backcross progeny was possible by means of electrophoretic markers. The main findings are as follows. One chromosome supresses viability when in the heterospecific state, this being mainly so when the rest of the genotype is predominantly of mojavensis type; the other chromosomes show occasional interspecific heterosis, but are neutral in the majority of cases; interactions are not significant, except in one pair of chromosomes within a mojavensis background; there is no correlation between numbers of heterospecific chromosomes and viability scores. It is concluded that hybrid and backcross progeny inviability is not a very potent mechanism for keeping these species apart. Should etiological and ecological barriers break down, introgressive hybridization is a real possibility. The findings are compared with those from studies concerning hybrid sterility and mating behavior in these two species. It is concluded that there is no common chromosomal basis for these phenomena. In particular, the role of interspecific inversions to speciation remains obscure.

Reproductive barriers and hybridity in two spruces, Picea rubens and Picea mariana, sympatric in eastern North America

2005 ◽  
Vol 83 (2) ◽  
pp. 163-175 ◽  
Author(s):  
John E Major ◽  
Alex Mosseler ◽  
Kurt H Johnsen ◽  
Om P Rajora ◽  
Debby C Barsi ◽  
...  
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Common Garden ◽  
Picea Rubens ◽  
Reproductive Phenology ◽  
Interspecific Crosses ◽  
Hybrid Index ◽  
Morphometric Traits ◽  
Seedling Traits ◽  
Species Specific

Hybridization between red spruce (Picea rubens Sarg.) and black spruce (Picea mariana (Mill.) BSP), late- and early-successional species, respectively, has resulted in identification and management problems. We investigated the nature and magnitude of reproductive and life-cycle success barriers in controlled intra- and inter-specific crosses of red and black spruce. We quantified a number of reproductive, germination, phenological, and performance traits, and examined traits by parental pedigree and hybrid index. Species' pollen had no effect on number of aborted or nonpollinated ovules. Controlled intraspecific crosses had, on average, 6.6 times more filled seeds than interspecific crosses. Cone and seed morphometric traits were species specific, with seed traits showing negative hybridization effects on both species. Germination, cotyledon number, and seedling height had significant species-specific traits, with hybrids showing an additive or slightly negative heterosis. Severe, negative heterosis appears to be of limited importance as an isolating barrier between red and black spruce. Reproductive phenology was remarkably similar among species and hybrid progenies when grown in common garden experiments. Crossability barriers are clearly paramount in maintaining the separation of the species. Ecological separation based on ecophysiological differences (e.g., shade tolerance) also represents an important prezygotic barrier for minimizing the negative effects of hybridization (e.g., postzygotic inviability) on reproductive fitness.Key words: cone, seed and seedling traits, genetic variation, phenology, red and black spruce.

Carbon assimilation variation and control in Picea rubens, Picea mariana, and their hybrids under ambient and elevated CO2

Trees ◽  
2013 ◽  
Vol 28 (2) ◽  
pp. 329-344 ◽  
Author(s):  
John E. Major ◽  
Alex Mossler ◽  
Debby C. Barsi ◽  
Moira Campbell ◽  
John Malcolm
Keyword(s):  
Elevated Co2 ◽  
Picea Mariana ◽  
Carbon Assimilation ◽  
Picea Rubens ◽  
And Control

A high-density genetic linkage map of a black spruce (Picea mariana) × red spruce (Picea rubens) interspecific hybrid

Genome ◽  
2011 ◽  
Vol 54 (2) ◽  
pp. 128-143 ◽  
Author(s):  
Bum-Yong Kang ◽  
John E. Major ◽  
Om P. Rajora
Keyword(s):  
Picea Mariana ◽  
Interspecific Hybrid ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Black Spruce ◽  
Picea Rubens ◽  
Red Spruce ◽  
Linkage Groups ◽  
Genomic Resource ◽  
Map Distance

Genetic maps provide an important genomic resource of basic and applied significance. Spruce ( Picea ) has a very large genome size (between 0.85 × 1010 and 2.4 × 1010 bp; 8.5–24.0 pg/1C, a mean of 17.7 pg/1C ). We have constructed a near-saturated genetic linkage map for an interspecific backcross (BC1) hybrid of black spruce (BS; Picea mariana (Mill.) B.S.P.) and red spruce (RS; Picea rubens Sarg.), using selectively amplified microsatellite polymorphic loci (SAMPL) markers. A total of 2284 SAMPL markers were resolved using 31 SAMPL–MseI selective nucleotide primer combinations. Of these, 1216 SAMPL markers showing Mendelian segregation were mapped, whereas 1068 (46.8%) SAMPL fragments showed segregation distortion at α = 0.05. Maternal, paternal, and consensus maps consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12) of 12 in the genus Picea. The maternal BS map consisted of 814 markers distributed over 12 linkage groups, covering 1670 cM, with a mean map distance of 2.1 cM between adjacent markers. The paternal BS × RS map consisted of 773 markers distributed over 12 linkage groups, covering 1563 cM, with a mean map distance of 2.0 cM between adjacent markers. The consensus interspecific hybrid BC1 map consisted of 1216 markers distributed over 12 linkage groups, covering 1865 cM (98% genome coverage), with a mean map distance of 1.5 cM between adjacent markers. The genetic map reported here provides an important genomic resource in Picea, Pinaceae, and conifers.

Growth and allocation of Picea rubens, Picea mariana, and their hybrids under ambient and elevated CO2

2015 ◽  
Vol 45 (7) ◽  
pp. 877-887 ◽  
Author(s):  
John E. Major ◽  
Alex Mosseler ◽  
Kurt H. Johnsen ◽  
Moira Campbell ◽  
John Malcolm
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Negative Relationship ◽  
Growth Efficiency ◽  
Picea Rubens ◽  
Tree Size ◽  
Total Biomass ◽  
Hybrid Index ◽  
Shoot To Root Ratio ◽  
Size Interaction

Red spruce (RS; Picea rubens Sarg.) – black spruce (BS; Picea mariana (Mill.) B.S.P.) controlled crosses (100%, 75%, 50%, 25%, and 0% RS, balance BS) showed increasingly greater height with increasing proportion of BS in each successive year. Height growth of 4-year-old ambient CO2 (aCO2) grown trees was highly correlated with height of 22-year-old field-grown trees of the same or similar crosses. Bud flush was earliest in BS and declined linearly with increasing proportion of RS with no significant CO2 effect. Percent stem (stem + branches) mass increased under elevated CO2 (eCO2), a quarter of which was due to ontogeny. Conversely, percent needle mass had a significant negative relationship with increasing tree size, and there was a CO2 × tree size interaction. Shoot-to-root ratio was greatest for BS, whereas RS had among the lowest. Hybrid index (HI) 50 had the greatest root mass allocation, lowest shoot-to-root ratio, and among the greatest total mass under eCO2. Growth efficiency increased with tree size and eCO2 but decreased with HI. Percent total biomass stimulation under eCO2 was lowest for BS at 6.5%, greatest for HI 50 at 20.3%, and RS had 17.5%.

scholarly journals Penstemon: A Summary of Interspecific Crosses

HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 494-498 ◽  
Author(s):  
Dale T. Lindgren ◽  
Daniel M. Schaaf
Keyword(s):  
Plant Breeding ◽  
Seed Production ◽  
Interspecific Crosses ◽  
Central Research ◽  
Parent Species ◽  
West Central ◽  
University Of Nebraska Lincoln ◽  
The University ◽  
Extension Center ◽  
Insight Into

Documenting the successful interspecific crosses in a genus is a valuable tool in making decisions in developing strategies for plant breeding activities. However, summarizing the breeding and hybridization can be confusing because of incomplete or lost breeding records and the failure to register the parentage of new cultivar names. A summary of interspecific crosses in the genus Penstemon at the University of Nebraska–Lincoln West Central Research and Extension Center over 10 years provides insight into both successful and unsuccessful crosses. The results, based on seed production and percent of successful crosses, would suggest that interspecific crosses are more likely to be successful when the parent species are more closely related.

Negative heterosis not apparent in 22-year-old hybrids of Picea mariana and Picea rubens

1998 ◽  
Vol 76 (3) ◽  
pp. 434-439 ◽  
Author(s):  
Kurt H. Johnsen ◽  
John E. Major ◽  
Judy Loo ◽  
Donald McPhee
Keyword(s):  
Picea Mariana ◽  
Picea Rubens
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