Supplemental materials of Miscanthus and sugarcane flowering management study
Creators: name: Hongxu Dong
name: Clark, Lindsay V.
name: Xiaoli Jin
name: Kossonou Anzoua
name: Bagmet, Larisa
name: Chebukin, Pavel
name: Dzyubenko, Elena
name: Dzyubenko, Nicolay
name: Bimal Kumar Ghimire
name: Heo, Kweon
name: Johnson, Douglas A.
name: Nagano, Hironori
name: Sabitov, Andrey
name: Junhua Peng
name: Yamada, Toshihiko
name: Yoo, Ji Hye
name: Yu, Chang Yeon
name: Zhao, Hua
name: Long, Stephen P.
name: Sacks, Erik J.
Publisher: name: figshare
Year: 2020
Subjects: subject: 70302 Agronomy
subject: FOS: Agriculture, forestry and fisheries
subject: FOS: Agriculture, forestry and fisheries
subject: 70305 Crop and Pasture Improvement (Selection and Breeding)
subject: 70304 Crop and Pasture Biomass and Bioproducts

description: <i>Miscanthus</i> is a close relative of <i>Saccharum</i> and a potentially valuable genetic resource for improving sugarcane.<i></i>Differences in flowering time within and between <i>Miscanthus</i> and <i>Saccharum</i> hinders intra- and interspecific hybridizations. A series of greenhouse experiments were conducted over three years to determine how to synchronize flowering time of <i>Saccharum</i> and <i>Miscanthus</i> genotypes. We found that day length was an important factor influencing when <i>Miscanthus</i> and <i>Saccharum</i> flowered<i>.</i> Sugarcane could be induced to flower in a central Illinois greenhouse using supplemental lighting to reduce the rate at which days shortened during the autumn and winter to 1 min d<sup>-1</sup>, which allowed us to synchronize the flowering of some sugarcane genotypes with <i>Miscanthus</i> genotypes primarily from low latitudes. In a complementary growth chamber experiment, we evaluated 33 <i>Miscanthus</i> genotypes, including 28 <i>M. sinensis, </i>2 <i>M. floridulus, </i>and 3<i> M. ×giganteus </i>collected from 20.9° S to 44.9° N for response to three day lengths (10 h, 12.5 h, and 15 h). High latitude-adapted <i>M. sinensis</i> flowered mainly under 15 h days, but unexpectedly, short days resulted in short, stocky plants that did not flower; in some cases, flag leaves developed under short days but heading did not occur. In contrast, for <i>M. sinensis</i> and <i>M. floridulus</i> from low latitudes, shorter day lengths typically resulted in earlier flowering, and for some low latitude genotypes, 15 h days resulted in no flowering. However, the highest ratio of reproductive shoots to total number of culms was typically observed for 12.5 h or 15 h days. Latitude of origin was significantly associated with culm length, and the shorter the days, the stronger the relationship. Nearly all entries achieved maximal culm length under the 15 h treatment, but the nearer to the equator an accession originated, the less of a difference in culm length between the short-day treatments and the 15 h day treatment. Under short days, short culms for high-latitude accessions was achieved by different physiological mechanisms for <i>M. sinensis</i> genetic groups from the mainland in comparison to those from Japan; for mainland accessions, the mechanism was reduced internode length, whereas for Japanese accessions the phyllochron under short days was greater than under long days. Thus, for <i>M. sinensis</i>, short days typically hastened floral induction, consistent with the expectations for a facultative short-day plant. However, for high latitude accessions of <i>M. sinensis</i>, days less than 12.5 h also signaled that plants should prepare for winter by producing many short culms with limited elongation and development; moreover, this response was also epistatic to flowering. Thus, to flower<i> M. sinensis</i> that originates from high latitudes synchronously with sugarcane, the former needs day lengths &gt;12.5 h (perhaps as high as 15 h), whereas that the latter needs day lengths &lt;12.5 h.