Showing papers by "Lidia Poggio published in 1998"
TL;DR: There is an optimum nucleotype for each population and that Bs are tolerated so long as this nucleotype is not exceeded, and analysis of total DNA content and the number of DAPI bands indicates that in populations with high A-DNA content the increase in genome size could be masked.
99 citations
TL;DR: There is a maximum limit to the mass of nuclear DNA so that Bs are tolerated as long as this maximum limit is not exceeded, and this indicates that there is a close interrelationship between the DNA content of A chromosomes and doses of Bs.
Abstract: Twenty-one native populations (1120 individuals) of maize from Northern Argentina were studied. These populations, which belong to 13 native races, were cultivated at different altitudes (80‐3620 m). Nineteen of the populations analyzed showed B chromosome (Bs) numerical polymorphism. The frequency of individuals with Bs varied from 0 to 94%. The number of Bs per plant varied from 0 to 8 Bs, with the predominant doses being 0, 1, 2, and 3. Those populations with varying number of Bs showed a positive and statistically significant correlation of mean number of Bs with altitude. The DNA content, in plants without Bs (A-DNA)(2n 5 20), of 17 populations of the 21 studied was determined. A 36% variation (5.0‐6.8 pg) in A-DNA content was found. A significant negative correlation between A-DNA content and altitude of cultivation and between A-DNA content and mean number of Bs was found. This indicates that there is a close interrelationship between the DNA content of A chromosomes and doses of Bs. These results suggest that there is a maximum limit to the mass of nuclear DNA so that Bs are tolerated as long as this maximum limit is not exceeded.
58 citations
TL;DR: Significant differences were found between the meiotic behaviour of V. graminea and that of the other species, and evolutionary changes in DNA amount are proportional to the relative length of each chromosome arm, maintaining karyotypic uniformity.
43 citations
TL;DR: The results show that B-TR is genetically controlled by the 0B female parents irrespective of the Bs of the male parent and that these genes are located on the A chromosomes.
Abstract: In previous papers we found that the frequency of B chromosomes in native races of maize varies considerably in different populations. Moreover, we found genotypes that control high and low transmission rates (TR) of B chromosomes in the Pisingallo race. In the present work crosses were made to determine whether the genes controlling B-TR are located on the normal chromosome set (As) or on the B chromosomes (Bs). We made female f.0B 3 male m.2B crosses between and within high (H) and low (L) B-TR groups. The Bs were transmitted on the male side in all cases. The mean B-TR from the progeny of f.0B (H) 3 m.2B (H) and f.0B (H) 3 m.2B (L) crosses was significantly higher than that from f.0B (L) 3 m.2B (L) and f.0B (L) 3 m.2B (H) crosses. The results show that the B-TR of the crosses corresponds to the H or L BTR of the 0B female parents irrespective of the Bs of the male parent. This indicates that B-TR is genetically controlled by the 0B female parent and that these genes are located on the A chromosomes.
21 citations
TL;DR: Numerical analysis allowed to differentiate the species studied and each of the populations within a same species, and the results here obtained agree fairly well with the interespecific relationships previously published in the genus Berberis.
Abstract: Phenetic relationships among II species belonging to the genus Berberis from 46 populations of NW Patagonia Argentina, were studied using numerical techniques. The species are B. bidentata Lechl., B. buxifolia Lam., B. cabrerae Job, B. chillanensis Sprag. ex Sandwith, B. darwinii Hook., B. empetrifolia Lam., B. heterophylla Juss., B. linearifolia Phil., B. montana Gay, B. parodii Job and B. serrato-dentata Lechl. Fifty four morphological characters were defined (24 vegetative and 30 reproductive). Forty six populations (with a total of 288 individuals) were analyzed. Two main groups were distinguished from the phenogram. One consists of the populations of 10spiny species; the other one is only formed by populations of B. serrato-dentata (without - or rarely / with scarce little weak - spines). Numerical analysis allowed to differentiate the species studied and each of the populations within a same species. This may be related to microambiental agents conditioning the phenotype. The results here obtained agree fairly well with the interespecific relationships previously published in the genus Berberis .
8 citations