Behavior, Transmission, and Morphological Effects of Accessory Chromosomes in
            Panicum coloratum
            L.
            1

A collection of 47 accessions of Panicum coloratum was classified into five morphologically distinct types. One of these was uniformly hexaploid (2n = 54) and another was diploid (2n = 18). The other three were mainly tetraploid (2n = 36) but some pentaploid (2n = 45) plants and one septaploid (2n = 63) plant were found. Meiosis was regular in all euploid plants but nine univalents were usually present in the pentaploid plants. A variable number of accessory chromosomes were found in somatic and generative cells in some plants of two of the types, and hybridization studies indicated a close relationship between these. It is suggested that both tetraploids and hexaploids are allopolyploids and that the hexaploid has two genomes in common with the tetraploids. All accessions set adequate seed following open pollination, but shed seed readily at maturity. There was variation in the degree of self-incompatibility both within and between types. In some accessions up to 33% of the florets were capable of setting seed when self-pollinated. P. coloratum grew best and flowered earliest in long days (I6 hr) and a day temperature of 27-30°C.

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Variability in Components of Seed Production in Panicum coloratum L. 1

Crop Science ◽

10.2135/cropsci1969.0011183x000900010013x ◽

1969 ◽

Vol 9 (1) ◽

pp. 38-40 ◽

Cited By ~ 2

Author(s):

C. Jackson Hearn ◽

Ethan C. Holt

Keyword(s):

Seed Production ◽

Panicum Coloratum

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Apicidin biosynthesis is linked to accessory chromosomes in Fusarium poae isolates

BMC Genomics ◽

10.1186/s12864-021-07617-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Thomas E. Witte ◽

Linda J. Harris ◽

Hai D. T. Nguyen ◽

Anne Hermans ◽

Anne Johnston ◽

...

Keyword(s):

Fusarium Head Blight ◽

Crop Yields ◽

High Resolution Mass Spectrometry ◽

Gene Clusters ◽

Biosynthetic Gene ◽

Metabolome Analysis ◽

Head Blight ◽

Eastern Canada ◽

Fusarium Poae ◽

Accessory Chromosomes

Abstract Background Fusarium head blight is a disease of global concern that reduces crop yields and renders grains unfit for consumption due to mycotoxin contamination. Fusarium poae is frequently associated with cereal crops showing symptoms of Fusarium head blight. While previous studies have shown F. poae isolates produce a range of known mycotoxins, including type A and B trichothecenes, fusarins and beauvericin, genomic analysis suggests that this species may have lineage-specific accessory chromosomes with secondary metabolite biosynthetic gene clusters awaiting description. Methods We examined the biosynthetic potential of 38 F. poae isolates from Eastern Canada using a combination of long-read and short-read genome sequencing and untargeted, high resolution mass spectrometry metabolome analysis of extracts from isolates cultured in multiple media conditions. Results A high-quality assembly of isolate DAOMC 252244 (Fp157) contained four core chromosomes as well as seven additional contigs with traits associated with accessory chromosomes. One of the predicted accessory contigs harbours a functional biosynthetic gene cluster containing homologs of all genes associated with the production of apicidins. Metabolomic and genomic analyses confirm apicidins are produced in 4 of the 38 isolates investigated and genomic PCR screening detected the apicidin synthetase gene APS1 in approximately 7% of Eastern Canadian isolates surveyed. Conclusions Apicidin biosynthesis is linked to isolate-specific putative accessory chromosomes in F. poae. The data produced here are an important resource for furthering our understanding of accessory chromosome evolution and the biosynthetic potential of F. poae.

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