Abnormal Nucleolar Cycle in Microsporogenesis of Brachiaria decumbens(Gramineae).
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چکیده
منابع مشابه
Microsporogenesis in Brachiaria dictyoneura (Fig. & De Not.) Stapf (Poaceae: Paniceae).
Microsporogenesis was analyzed in five accessions of Brachiaria dictyoneura presenting x = 6 as the basic chromosome number. All accessions were tetraploid (2n = 4x = 24) with chromosome pairing in bi-, tri-, and quadrivalents. The recorded meiotic abnormalities were those typical of polyploids, including precocious chromosome migration to the poles, laggard chromosomes, and micronucleus format...
متن کاملEvaluation of microsporogenesis in an interspecific Brachiaria hybrid (Poaceae) collected in distinct years.
Microsporogenesis in an interspecific Brachiaria hybrid, grown in the field under natural environmental conditions in Brazilian savannas, was analyzed in three distinct years of collection. Several types of meiotic abnormalities were recorded during those three years, but varied in type and frequency depending on the year. The average temperature and rainfall 15 days before collection was unusu...
متن کاملMicrosporogenesis analysis validates the use of artificially tetraploidized Brachiaria ruziziensis in breeding programs.
The genus Brachiaria contains species that have great economic importance in the Brazilian agricultural sector, as they enable cattle ranching on acid and poor soils with species that are resistant to spittlebugs and form crop-livestock-forest integration systems. The genus mainly consists of tetraploid (2n = 4x = 36) and apomictic species such as B. decumbens and B. brizantha. Sexuality is fou...
متن کاملMitotic behavior in root tips of Brachiaria genotypes with meiotic chromosome elimination during microsporogenesis.
Three accessions of Brachiaria brizantha, three of B. humidicola, and two interspecific hybrids between B. ruziziensis and B. brizantha were analyzed with regard to their mitotic behavior in root tips. All these genotypes revealed chromosome elimination or lack of chromosome affinity in previous analyses of microsporogenesis. Analyses of root tips showed a normal mitotic division in all accessi...
متن کاملMicrosporogenesis in tetraploid accessions of Brachiaria nigropedata (Ficalho & Hiern) Stapf (Gramineae).
The genus Brachiaria (Trin.) Griseb. has achieved considerable importance to cattle production systems, as a result of the good production and adaptation of a few cultivars to poor and acid soils of the Brazilian savannas. Many of its species and accessions are polyploid and apomictic, which limits direct hybridization. To assist the breeding program, cytogenetic characterization has been under...
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ژورنال
عنوان ژورنال: CYTOLOGIA
سال: 2002
ISSN: 0011-4545,1348-7019
DOI: 10.1508/cytologia.67.355