. Cytological and genetic studies of sterility in inbred and hybrid maize. Sterility in plants; Corn; Corn; Hybrid corn; Hybrid corn. 714 Connecticut Experiment Station Bulletin 405 i l_. Figure ^. A. Normal chromosome 1. The arrows mark the approximate limits of the inversion. B. Inverted chromosome 1. C. Outline drawing of synapsis of normal and in- verted homologues at mid-prophase of meiosis. Plant 42G 8-1 (Pedigree 540X4-8). The centromere region in all drawings is indicated by the ligliter open circle. including centromeres are rarely reported (Sturtevant and Beadle 39, p. 189). They may
. Cytological and genetic studies of sterility in inbred and hybrid maize. Sterility in plants; Corn; Corn; Hybrid corn; Hybrid corn. 714 Connecticut Experiment Station Bulletin 405 i l_. Figure ^. A. Normal chromosome 1. The arrows mark the approximate limits of the inversion. B. Inverted chromosome 1. C. Outline drawing of synapsis of normal and in- verted homologues at mid-prophase of meiosis. Plant 42G 8-1 (Pedigree 540X4-8). The centromere region in all drawings is indicated by the ligliter open circle. including centromeres are rarely reported (Sturtevant and Beadle 39, p. 189). They may occur as frequently as other inversions, but the method of detecting them in maize by the presence of anaphase bridges and fragments does not alloAv the identificatiou of those inversions the centromere. The amount of jioHeu abortion in ])]auts from two of tlie ]iyl)rids is given in Table (>. Table 6. Counts of the Pollen Produckd by Four Plants Having a Hktkr- ozYGous Inversion on Chromosome 1. Pedigree Plant Normal pollen grains Empty grains Small â grains Total Percent aborted 187-2 y 4-8A 40-899-15 691 647 786 269 252 318 6 12 11 966 *)1] 1115 540 X 4-8 42G 2-3 42G 8-1 8-3 539 768 813 365 146 227 38 942 914 1040 Since a >iiiM|(. williiii llu'. inverted region results in two normal clironial ids and two delicient cliromatids from one sporocyte, the anioiinl of crossing o\-er is ap]»i'o\iinatel \' doubh^ th(> amount of ])ollen alioilion. II a jilaiit lielero/ygoiis for (he inxcr^ioii nn cliiiimosome 1 is (lie fesuHing progeny -lionld |ia\-e one foiii'tji plants with uor- mal clirojuosonie 1, one-foiirlli liomo/.ygons foi- (he invcrled ciiroMU)- some, 1 and oiie-lialf hetei'ozygous for (he inversion. If a |)lan( heter- o/ygoiis for (he invei'sion is used as either (he male or female paicnt. Please note that these images are extracted from scanned page images that may have been digitally enhanced for re
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