In this paper, we compare ndh genes in the plastid genome of many Cymbidium species and three closely related taxa in Orchidaceae looking for evidence of ndh gene degradation. Among the 11 ndh genes, there were frequently large deletions in directly repeated or AT-rich regions. Variation in these degraded ndh genes occurs between individual plants, apparently at population levels in these Cymbidium species. It is likely that ndh gene transfers from the plastome to mitochondrial genome (chondriome) occurred independently in Orchidaceae and that ndh genes in the chondriome were also relatively recently transferred between distantly related species in Orchidaceae. Four variants of the ycf1-rpl32 region, which normally includes the ndhF genes in the plastome, were identified, and some Cymbidium species contained at least two copies of that region in their organellar genomes. The four ycf1-rpl32 variants seem to have a clear pattern of close relationships. Patterns of ndh degradation between closely related taxa and translocation of ndh genes to the chondriome in Cymbidium suggest that there have been multiple bidirectional intracellular gene transfers between two organellar genomes, which have produced different levels of ndh gene degradation among even closely related species.

We assembled three complete mitochondrial genomes (mitogenomes), two of Solanum lycopersicum and one of Solanum pennellii, and analyzed their intra- and interspecific variations. The mitogenomes were 423,596–446,257 bp in length. Despite numerous rearrangements between the S. lycopersicum and S. pennellii mitogenomes, over 97% of the mitogenomes were similar to each other. These mitogenomes were compared with plastid and nuclear genomes to investigate genetic material transfers among DNA-containing organelles in tomato. In all mitogenomes, 9,598 bp of plastome sequences were found. Numerous nuclear copies of mitochondrial DNA (NUMTs) and plastid DNA (NUPTs) were observed in the S. lycopersicum and S. pennellii nuclear genomes. Several long organellar DNA fragments were tightly clustered in the nuclear genome; however, the NUMT and NUPT locations differed between the two species. Our results demonstrate the recent occurrence of frequent endosymbiotic gene transfers in tomato genomes.

Lilium pardalinum Kellogg is native to the Pacific Coast of the United States, and grows in woodland near streams. In the present study, the complete plastome of L. pardalinum was sequenced. The plastome sequence is 151,969 bp long with a large single copy, a small single copy, and two inverted repeat regions of length 81,401, 17,346, and 26,611 bp, respectively. A total of 133 genes were identified, including 82 coding genes, 8 ribosomal RNAs, 38 transfer RNAs, and 5 pseudogenes. Among the 5 pseudogenes, pseudo ndhF and ndhG genes were similar to that of L. washingtonianum and L. philadelphicum , respectively. Lilium pardalinum is sister to American lilies, except L. philadelphicum .

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Lilium washingtonianum Kellogg is native to Western America and grows on slope in high subalpine. In the present study, the complete plastome of L. washingtonianum was sequenced. The plastome sequence was 151,967 bp long, with a large single copy region of 81,393 bp, a small single copy region of 17,352 bp, and two inverted repeat regions of 26,611 bp each. Total 133 genes were identified, including 83 coding genes, 8 ribosomal RNAs, 38 transfer RNAs, and 4 pseudogenes. Among four pseudogenes, pseudo ndhF gene was the first to report among Lilium species so far. The phylogenetic position of L. washingtonianum was sister to L. superbum but American lilies were not monophyletic.