The south American wild bean (Phaseolus aborigineus Burk.) as ancestor of the common bean

1976 ◽  
Vol 30 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Ollie Berglund-Brücher ◽  
Heinz Brücher
Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 546-554 ◽  
Author(s):  
N. Mutlu ◽  
A. K. Vidaver ◽  
D. P. Coyne ◽  
J. R. Steadman ◽  
P. A. Lambrecht ◽  
...  

Both the common bacterial blight (CBB) pathogen (Xanthomonas campestris pv. phaseoli) and X. fuscans subsp. fuscans, agent of fuscous blight, cause indistinguishable symptoms in common bean, Phaseolus vulgaris. Yield losses can exceed 40%. Lack of information about the specificity between X. campestris pv. phaseoli strains and major quantitative trait loci (QTL) or alleles conferring resistance makes the task of identifying genetic changes in host–pathogen interactions and the grouping of bacterial strains difficult. This, in turn, affects the choice of pathogen isolates used for germplasm screening and complicates breeding for CBB resistance. Common bean host genotypes carrying various sources and levels of resistance to CBB were screened with 69 X. campestris pv. phaseoli and 15 X. fuscans subsp. fuscans strains from around the world. Differential pathogenicity of the CBB pathogen was identified on the 12 selected bean genotypes. The X. fuscans subsp. fuscans strains showed greater pathogenicity than X. campestris pv. phaseoli strains having the same origin. African strains were most pathogenic. The largest variation in pathogenicity came from X. campestris pv. phaseoli strains that originated in Caribbean and South American countries. Pathogenic variation was greater within X. campestris pv. phaseoli than within X. fuscans subsp. fuscans strains. Implications for breeding for CBB resistance are discussed.


2012 ◽  
Vol 25 (6) ◽  
pp. 432 ◽  
Author(s):  
Anthony Mitchell ◽  
Rong Li ◽  
Joseph W. Brown ◽  
Ines Schönberger ◽  
Jun Wen

Molecular genetic analyses were used to reconstruct phylogenetic relationships and estimate divergence times for Raukaua species and their close relatives. A monophyletic group identified as the ‘greater Raukaua clade’ was circumscribed, with eight representative species; its basal divergence was estimated at c. 70 Mya, possibly after Zealandia had separated from Gondwana. Raukaua is paraphyletic because of the placement of Motherwellia, Cephalaralia, Cheirodendron and Schefflera s.s. The phylogeny supports a more narrowly circumscribed Raukaua that includes the New Zealand but not the South American or Tasmanian representatives. Ancestors of the monophyletic South American and Tasmanian Raukaua and the mainland Australian Motherwellia and Cephalaralia diverged at c. 66 Mya and their current disjunction may be vicariant, with overland dispersal between Australia and South America, possibly via Antarctica. Vicariance is also a likely mechanism for divergence at c. 57 Mya of the monophyletic Motherwellia, Cephalaralia and Tasmanian Raukaua. The common ancestor of New Zealand Raukaua¸ Cheirodendron and Schefflera s.s. is inferred to have existed c. 62 Mya in New Zealand, before the marine incursions during the Oligocene, implying that New Zealand Raukaua and Schefflera s.s. survived the inundation period or speciated outside New Zealand and subsequently colonised. Ancestors of Cheirodendron split from New Zealand Raukaua c. 43 Mya and dispersed over vast expanses of the south-western Pacific to Hawaii.


2020 ◽  
Vol 60 ◽  
pp. e20206053
Author(s):  
Juan Camilo Arredondo ◽  
Felipe Gobbi Grazziotin ◽  
Gustavo Jose Scrocchi Manfrini ◽  
Miguel Trefaut Urbano Rodrigues ◽  
Sandro Luís Bonatto ◽  
...  

South American racers of the tribe Philodryadini are a widespread and diverse group of Neotropical snakes with a complex taxonomic and systematic history. Recent studies failed to present a robust phylogenetic hypothesis for the tribe, mainly due to incomplete taxon sampling. Here we provide the most extensive molecular phylogenetic analysis of Philodryadini available so far, including 20 species (83% of the known diversity) from which six were not sampled previously. Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines. This discovery requires resurrection of two genera as well as erection of a new tribe of Xenodontinae for the central Andean clade. Within the southern and cis-Andean radiation, our analyses resolve a basal dichotomy separating two main lineages: Clade A, containing the Common Green Racers P. laticeps and P. viridissima and the South American Vine snakes P. georgeboulengeri and P. argentea; and Clade B, including the remaining species of Philodryas sensu stricto. We resurrect the genera Chlorosoma and Xenoxybelis to better represent the monophyly of lineages within the southern and cis-Andean clade.


2020 ◽  
Vol 105 (2) ◽  
pp. 183-194
Author(s):  
Fernando O. Zuloaga ◽  
Sandra S. Aliscioni ◽  
M. Amalia Scataglini

Generic boundaries of the South American species Panicum longipedicellatum Swallen are explored and compared with allied genera of the tribe Paniceae. On the basis of morphological, anatomical, and molecular characters a new genus, Cnidochloa Zuloaga, is proposed. The phylogenetic position of the new genus within the Paniceae is evaluated.


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