Evolutionary biology of microcyclic rust fungi

本研究主要关注与锈菌变孢子产生有关的核行为与生命周期缩短的关系。在本研究中，我们新观察到与圆叶锈菌（Puccinia circaeae Pers）产生变孢子相关的核行为类型。， P. lantanae W. G. Farlow， P. nipponica Dietel， P. patriniae P. Hennings P. tiarellaecola Hiratsuka, f. and Endophyllum paederiae Stevens & Mendiola。在冬采沙蚕和亨宁斯采沙蚕中，观察到的变孢子产生模式与先前报道的相同。然而，核在生命周期中的行为与以往的报道有所不同。在该物种中观察到的核行为类型中，在circaeae中发现的核行为类型在udinales中是未知的。在这个物种中，核分裂发生在端孢子中，随后的第一次减数分裂发生在端孢子萌发后的变质孢子中。两个单倍体核被隔隔隔开，后胚轴变成两细胞。两个细胞各形成一个单核担子孢子。第二次减数分裂发生在担子孢子，孢子变成单倍体双核。据认为，同体化通常在锈菌的生命周期减少过程中进化。对于这种可能性，只有很少的实验证据。在本研究中，通过对单一担子孢子的接种，证实了Kuehneola japonica (Dietel) Dietel和p.l antanae是同源的，其中来自单个担子孢子的菌丝体产生了端部和端孢子。

This study primarily concerned with the nuclear behavior associated in the metabasidium production in relation to the reduction of the life cycle in the rust fungi. In this study, the types of nuclear behaviors associated in the metabasidium production were newly observed for Puccinia circaeae Pers., P. lantanae W. G. Farlow, P. nipponica Dietel, P. patriniae P. Hennings P. tiarellaecola Hiratsuka, f. and Endophyllum paederiae Stevens & Mendiola. In P. arenariae Winter and P. horiana P. Hennings, the observed mode of the metabasidium production was the same as that has previously been reported. However, the nuclear behavior in the life cycle was different from the previous reports.Among the nuclear behavior types observed in the species, the type found in Puccinia circaeae had not been known for the Uredinales. In this species, karyogamy took place in the teliospore and the subsequent first meiotic division occurred in the metabasidium upon germination of the teliospore. The two haploid nuclei were delimited by a septum and the metabasidium became two-celled. From each of the two cells, a uninucleate basidiospore was formed. The second meiotic division took place in the basidiospore, the spore becoming haploid binucleate.It has been suggested that homothallism often evolves during the life-cycle reduction in the rust fungi. There have been only a few experimental proofs for this possibility. In this study, Kuehneola japonica (Dietel) Dietel and P. lantanae were proven to be homothallic by a single basidiospore inoculation, where the mycelium derived from a single basidiospore produced the telium and the teliospore.