Institute for Horticultural Production Systems, Leibniz University Hannover, Herrenhäuser Straße 2, 30419, Hannover, Germany.
Planta. 2023 Aug 5;258(3):62. doi: 10.1007/s00425-023-04218-9.
Susceptibility to neck shrivel in European plum is due to cuticular microcracking resulting from high surface area growth rates in the neck region, late in development. Susceptibility to the commercially important fruit disorder 'neck shrivel' differs among European plum cultivars. Radial cuticular microcracking occurs in the neck regions of susceptible cultivars, but not in non-susceptible ones, so would seem to be causal. However, the reason for the microcracking is unknown. The objective was to identify potential relationships between fruit growth pattern and microcracking incidence in the neck (proximal) and stylar (distal) ends of selected shrivel-susceptible and non-susceptible cultivars. Growth analysis revealed two allometric categories: The first category, the 'narrow-neck' cultivars, showed hypoallometric growth in the neck region (i.e., slower growth than in the region of maximum diameter) during early development (stages I + II). Later (during stage III) the neck region was 'filled out' by hyperallometric growth (i.e., faster than in the region of maximum diameter). The second category, the 'broad-neck' cultivars, had more symmetrical, allometric growth (all regions grew equally fast) throughout development. The narrow-neck cultivars exhibited extensive radial cuticular microcracking in the neck region, but little microcracking in the stylar region. In contrast, the broad-neck cultivars exhibited little microcracking overall, with no difference between the neck and stylar regions. Across all cultivars, a positive relationship was obtained for the level of microcracking in the neck region and the difference in allometric growth ratios between stage III and stages I + II. There were no similar relationships for the stylar region. The results demonstrate that accelerated stage III neck growth in the narrow-neck plum cultivars is associated with more microcracking and thus with more shrivel.
欧洲李易患颈部皱缩，这是由于颈部区域高表面积增长率导致的角质层微裂，出现在发育后期。欧洲李品种对商业上重要的果实失调“颈部皱缩”的易感性不同。易感品种的颈部区域会发生放射状角质层微裂，但非易感品种则不会，因此似乎是因果关系。然而，微裂的原因尚不清楚。本研究的目的是确定选定的易受皱缩影响和不易受皱缩影响的品种的果实生长模式与颈部（近轴）和花柱（远轴）端微裂发生率之间的潜在关系。生长分析揭示了两种异速生长类别：第一类，“窄颈”品种，在早期发育（I+II 期）期间，颈部区域的生长呈亚异速生长（即生长速度比最大直径区域慢）。后来（在 III 期），颈部区域通过超异速生长（即比最大直径区域快）“填满”。第二类，“宽颈”品种，整个发育过程中具有更对称的异速生长（所有区域生长速度相同）。窄颈品种在颈部区域表现出广泛的放射状角质层微裂，但在花柱区域微裂很少。相比之下，宽颈品种整体微裂较少，颈部和花柱区域之间没有差异。在所有品种中，颈部区域微裂程度与 III 期与 I+II 期之间的异速生长比差异呈正相关。花柱区域没有类似的关系。结果表明，窄颈李品种 III 期颈部生长加速与更多微裂有关，从而导致更多皱缩。
