Limoniibacter endophyticus gen. nov., sp. nov., an alphaproteobacterium isolated from the roots of Limonium otolepis.

A Gram-negative bacterium, designated as strain YIM 690229T, was isolated from the roots of Limonium otolepis. The strain was able to grow at 10-40 °C (optimum, 28-37 °C), pH 6.0-8.0 (optimum, 7.0) and in the presence of up to 7% NaCl (w/v) (optimum, up to 2.5%). Comparative 16S rRNA gene sequence analysis revealed that strain YIM 690229T shared less than 93.9% sequence similarities with members within the order Rhizobiales, and was remotely related to members of the family Hyphomicrobiaceae. Strain YIM 690229T was characterized by the presence of Q-10 as the predominant respiratory lipoquinone. The major fatty acids (> 10%) detected were C18:1 ω7c, C16:0, anteiso-C15:0 and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). The polar lipids consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanoamine and two unidentified lipids. The genomic DNA G + C content was 57.2 mol%. Data from this polyphasic taxonomy study suggested that strain YIM 690229T should be classified as a new species of a new genus within the family Hyphomicrobiaceae for which the name Limoniibacter endophyticus gen. nov., sp. nov., is proposed. The type species of the genus Limoniibacter gen. nov. is Limoniibacter endophyticus. The type strain of the species Limoniibacter endophyticus sp. nov. is YIM 690229T (= KCTC 42097T = JCM 30141T = CCTCC AB 2014130T = CGMCC 1.12906T).

Floral morph variation mediated by clonal growth and pollinator functional groups of Limonium otolepis in a heterostylous fragmented population.

Abstract. Heterostyly, a genetic style polymorphism, is linked to symmetric pollen transfer, vital for its maintenance. Clonal growth typically impacts sexual reproduction by influencing pollen transfer. However, the floral morph variation remains poorly understood under the combined effects of pollinators and clonal growth in heterostyly characterized by negative frequency-dependent selection and disassortative mating. We estimated morph ratios, ramets per genet and heterostylous syndrome and quantified legitimate pollen transfer via clonal growth, pollinators and reciprocal herkogamy between floral morphs in Limonium otolepis, a fragmented population composed of five subpopulations in the desert environment of northwestern China, with small flower and large floral morph variation. All subpopulations but one exhibited pollen-stigma morphology dimorphism. The compatibility between mating types with different pollen-stigma morphologies remained consistent regardless of reciprocal herkogamy. Biased ratios and ramets per genet of the two mating types with distinct pollen-stigma morphologies caused asymmetric pollen flow and varying fruit sets in all subpopulations. Short-tongued insects were the primary pollinators due to small flower sizes. However, pollen-feeding Syrphidae sp. triggered asymmetry in pollen flow between high and low sex organs, with short-styled morphs having lower stigma pollen depositions and greater variation. Clonal growth amplified this variation by reducing intermorph pollen transfer. All in all, pollinators and clonal growth jointly drive floral morph variation. H-morphs with the same stigma-anther position and self-incompatibility, which mitigate the disadvantages of sunken low sex organs with differing from the classical homostyly, might arise from long- and short-styled morphs through a 'relaxed selection'. This study is the first to uncover the occurrence of the H-morph and its associated influencing factors in a distylous plant featuring clonal growth, small flowers and a fragmented population.