AN ANALYSIS OF THE INFLUENCE OF CLONE SIZE AND STOLON CONNECTIONS BETWEEN RAMETS ON THE GROWTH OF GLECHOMA HEDERACEA L.

Abstract

SUMMARYTwo experiments were conducted in which the influence of size of clones and the persistence of stolon connections on subsequent development were examined in Gtechoma hederacea. In the first experiment, clones were grown from either one unrooted ramet or from either one, two or three connected, rooted ramets, for 8 weeks, in either nutrient-rich or nutrient-poor sand. The survival, number of ramets and dry weight of the clones produced were dependent on the number of established ramets at the start of the experiment. Clones in nutrient-rich sand developed a greater number of ramets, stolon branches, total length of stolon, mean leaf area per ramet and total leaf area per clone than clones of corresponding initial size in nutrient-poor sand. In the second experiment, the stolon connections between ramets of G. hederacea clones growing in boxes were either left intact or severed soon after each ramet had rooted. After 10 weeks of growth, the total dry weight of the intact clones and the mean dry weight of their ramets were significantly greater than the corresponding values for severed clones. The spatial distribution of ramets showed marked differences between the treatments. Severed clones produced a greater number of rooted ramets within the boxes and a smaller number of unrooted ramets beyond the box edges than intact clones. Density of ramets more than doubled when stolons were severed.Maintenance of stolon connections in G. hederacea is advantageous because it improves the probability of daughter ramet survival, promotes rapid lateral expansion of the clone and reduces inter-ramet competition through the production of fewer, larger ramets.

Effects of Aspect on Clonal Reproduction and Biomass Allocation of Layering Modules of Nitraria tangutorum in Nebkha Dunes

“…This result was opposite to our second hypothesis. Sprouting of intact clones would result in the ramet increment and the adjustment of biomass allocation to ensure normal growth and development [29], [49], in which clonal integration plays an important role in the clonal growth [21], [27], [38]. The clonal growth differences were attributed to the amount of stored resources in the previous studies for the stolon or rhizome fragment [29], [33], [50].…”

“…buds on the layering that are the primary shoot-producing meristematic organs [34], [35], [36], [37], [38]. The clonal growth of a size-dependent clone is common [33], [38], [39], [40], [41]. One study found that the big Glechoma hederacea clone developed a greater number of ramets under favorable conditions [38].…”

“…The clonal growth of a size-dependent clone is common [33], [38], [39], [40], [41]. One study found that the big Glechoma hederacea clone developed a greater number of ramets under favorable conditions [38]. However, little is known about the effect of layering size.…”

Glechoma hederaceaL. (Nepeta glechomaBenth.,N. hederacea(L.) Trev.)

“…Translocation of resources from older to younger ramets increases the probability of daughter ramet survival (Slade & Hutchings 1987a). Physiological integration appears to involve no costs, at least in biomass terms, to the source ramet, but confers growth benefits upon the whole clone (Slade & Hutchings 1987b).…”

“…Stolon breakage reduces the capacity of clones to spread laterally, and smaller ramets are produced. Severing the stolons between ramets resulted in ramets being established at more than twice the density seen in intact clones (Slade & Hutchings 1987a).…”