A separate control for frequency and within-bivalent distribution of chiasmata in rye (Secale cereale L.)

Abstract

LEIN, V., and LELLEY, T. 1987. A separate control for frequency and within-bivalent distribution of chiasmata in rye (Secale cereale L.). Genome, 29: 4 19-424. Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in the average number and in the positional distribution of chiasmata were used in this study. The line with the lowest chiasma frequency was chosen as the female parent and crossed with the other five lines. Parental, F, , and F2 data were collected on chiasma number and on chiasma distribution between and within bivalents. Evidence for a polygenic control of both phenomena was found. Chiasma distribution between bivalents within pollen mother cells obviously follows a binomial distribution. This is effected by a mechanism that prevents the formation of a second chiasma on a chromosome arm as long as chromosome arms without chiasma remain; i.e., with 14 chiasmata seven ring bivalents will generally be formed. This mechanism causes a very strong negative correlation between frequency and between-cell variance of chiasmata. The number of chiasmata is independent of their position within the bivalents. A very close correlation between the number of pollen mother cells without univalents and the number of fertile pollen grains was found.Key words: inbred rye, genetic control, chiasma frequency, chiasma distribution, heterosis.LEIN, V., et LELLEY, T. 1987. A separate control for frequency and within-bivalent distribution of chiasmata in rye (Secale cereale L.). Genome, 29 : 4.19-424. Six genotypes consanguins gknktiquement diffkrents de seigle de printemps, Secale cereale, qui prksentent des diffkrences quant au nombre moyen de chiasmata et a la distribution de leur position, ont kt6 utilisks pour la prksente etude. La lignke dont la frkquence des chiasmata ktait la plus faible a kt6 choisie comme parent femelle et croiske avec les cinq autres lignkes. Les donnkes relatives au nombre de chiasmata et a leur distribution entre et a I'intkrieur des bivalents ont kt6 prises chez les parents et chez les descendances F1 et F2. L'kvidence qu'il existe un contr6le polygknique pour les deux phknomenes a kt6 trouvke. La distribution des chiasmata entre bivalents chez les cellules-meres des grains de pollen s'opere selon une distribution binomiale. Ceci s'effectue par un mkcanisme qui empeche la formation d'un second chiasma sur un meme bras chromosomique aussi longtemps qu'il existe des bras de chromosomes sans chiasma; ainsi, 14 chiasmata conduiront gknkralement a la formation de sept bivalents en anneaux. Ce mkcanisme cause une corrklation tres fortement negative entre la frkquence des chiasmata et la variance entre cellules. Le nombre de chiasmata est indkpendant de la position de ces derniers a l'intkrieur des bivalents. Une tres ktroite corrklation a kt6 trouvke, cependant, entre le nombre de cellules-meres de pollen qui ne possedent pas d'univalents et le nombre de grains de pollen fertiles.

Chromosomal Behaviour and Seed Production in Chlorophytum comosum (Liliaceae).

“…These authors did not find any bivalents with one chiasma, whereas we detected a mean of 5.45 bivalents among the fourteen present in each microsporocyte, with only one chiasma and more than a half of these (M=2.92) showing a terminal chiasma. Since chiasma frequency (Rees and Thompson 1958, Pagliarini 1980, Karp and Jones 1982, Lein and Lelley 1987 and chiasma distribution (Jones 1967, Karp and Jones 1983, Lein and Lelley 1987 are under genetic control, the difference between the plants analysed here and the plants analysed by Patil and Gandhi (1988) could be of a genetic nature. Absence of chiasma and precocious chiasma terminalization have been reported to be respon sible for the occurrence of univalents in maize (Pagliarini 1980(Pagliarini , 1989, Aptenia cordifolia (Pagliarini 1990), and Pilocarpus pennatifolius (Pagliarini and Pereira 1992).…”

Research Note ms17: a meiotic mutation causing partial male sterility in a corn silage hybrid

“…Table 1 presents the frequency of affected cells. Besides the polygenes controlling the chiasma frequency (Rees and Thompson, 1956;Lein and Lelley, 1987), two other categories of genes can affect synapsis. The asynaptic genes hinder chromosome pairing (Gottschalk and Kaul, 1980a) while the desynaptic genes promote desynapsis in bivalents before metaphase I (Gottschalk and Kaul, 1980b).…”

Meiotic behavior in wild and domesticated species of Passiflora

“…In maize (Zea mays L.), the frequency of chiasmata is under polygenic control, which may lead to genetic variability in lineages (Pagliarini 1980). The polygenic chiasma control has also been demonstrated in rye, Secale cerale (Rees & Thompson 1958, Lein & Lelley 1987. The formation of chiasmata is a good characteristic, since it ensures the genetic variability of plants, thus having a direct influence on the adaptation mechanisms.…”