Studies of Asynapsis in Rye

A Case of Asyndesis in Picea Abies

“…16) if the separation of chromalids or possibly of only longitudinally divided univalents wit11 undivided centroinere takes place before tlie daughter-nuclei h v e invested thein-\elves in :I ccll-membrane. (PRAKKEN, 1943). In Picea Ahies split univalents occur in anaphase I not only in cells with one or inore bivalents, which may be regarded as cells with partial asynapsis, but also and niost frequently in cells that have no bivalents.…”

Methyl methane sulphonate induced desynaptic mutants in Capsicum annuum L.

“…Occurrence of univalents at diakinesis and metaphase I in the mutants could be attributed to failure of chiasma formation. The univalents and bivalents varied considerably from PMC to PMC in both plants (Table 1) and the desynapsis fitted into the medium strong category of Prakken (1943). Inter PMC frequency variation of bivalents in the mutant plant suggested that the response of different chromosome of a genome to the influence of mutated gene might be variable and independent (Koduru and Rao, 1981).…”

“…The univalent classes "weak" and "medium strong" desynaptic have been recovered from each of the segregating generation (Table 3). Such deviations in pairing frequency in F 2 are attributed to modifying genes (Koller 1983;Subbarao 1980), and environmental factor (Prakken 1943 Table 2. Chromosome distribution at anaphase I in two desynaptic mutants of Capsicum annuum var.…”

“…χ 2 test was applied for inheritance of desynapsis using F 2 data. The F 2 segregating families were scored as normal or desynaptic and the latter were classified following Prakken (1943). …”

Induced desynaptic variation in poppy (Papaver somniferum L.)

“…Meiotic configurations were observed in metaphase I and anaphaseI. Prakken (1943), on the basis of univalent frequency, divided the desynaptic mutant into weak, medium strong and strong types: weak, with few univalents in some of the cells; medium strong, with many univalents in most of the cells; and strong with univalents only, or some rare bivalents. Thus, taking into account the frequency of univalents found at metaphase I, it could be said to be of medium strong type.Pollen grains were also stained with 2% acetocarmine to study pollen fertility; undersized and unstained pollen grains were considered inviable.…”