Sex ratios and clonal growth in dioecious Populuseuphratica Oliv., Xinjiang Prov., Western China
Sex ratios and clonal growth in dioecious Populuseuphratica Oliv., Xinjiang Prov., Western China
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DOI：
10.1007/s00468-012-0828-y
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
A. Petzold;T. Pfeiffer;F. Jansen;P. Eusemann;M. Schnittler
中科院分区：
文献类型：
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作者：
A. Petzold;T. Pfeiffer;F. Jansen;P. Eusemann;M. Schnittler
利用微卫星分析技术，研究了新疆胡杨无性系无性系所有级别的性别比例都倾向于雄性偏向（3，295棵开花树中有60%是雄性），尽管雄性过剩在基因组水平上最不明显（850个基因组中有52%是雄性）。男性克隆包括显着更多（708比572）比女性克隆树。生殖投资是根据雄性和雌性生殖器官的碳（C）和氮（N）含量来衡量的：单花或果荚，整个花序或果序，和ca.直径2厘米。雄花和柔荑花序比雌果和柔荑花序需要更少的N，但平均只有16%的雌花柔荑花序发育成果实。这就改变了在分支水平上测量的繁殖投资：现在男性分支花费的N是女性分支的3.3倍。这与树枝的年增长量相吻合，作为繁殖成本的一种可能的权衡：雌性树枝需要2年才能达到2厘米的直径。我们的结论是，完整的女性坐果会给男性一个沉重的比较优势，但频繁流产的整个fructescences的女性似乎是一个强大的机制，以补偿更高的生殖努力，从而避免了显着失控的影响，更有力的克隆生长的男性树木在很长一段时间。
Using a microsatellite assay, we investigated sex ratios at three levels (apparent, intrinsic, genet) forPopuluseuphraticastands in Xinjiang, China and possible consequences of sex-specific costs of reproduction in terms of clonal growth and individual growth or mortality. Sex ratios at all levels tended to be male biased (60 % of 3,295 flowering trees were male), although male excess was least pronounced at the genet level (52 % of 850 genets were male). Male clones comprised significantly more (708 vs. 572) trees than female clones. Reproductive investment was measured in terms of carbon (C) and nitrogen (N) contents of male and female reproductive organs: single flowers or fruit capsules, whole inflorescences or infructescences, and whole branches of ca. 2 cm diameter. Male flowers and catkins require less N than female fruits and catkins, but on average only 16 % of female catkins develop into fruits. This changes the measured investment for reproduction at branch level: now male branches spent 3.3 times more N than their female counterparts. This coincides with the annual increment of branches, measured as a possible trade-off for costs of reproduction: female branches needed 2 years less to reach a diameter of 2 cm. We conclude that full fruit set of females would give males a heavy comparative advantage, but frequent abortion of whole infructescences by females seems to be a powerful mechanism to compensate a higher reproductive effort, thus avoiding a pronounced runaway effect by more vigorous clonal growth of male trees over a long time.