Department of Breeding, Physiology of Plants and Seed Science, Faculty of Agriculture and Economics, University of Agriculture of Krakow, Podłużna 3, 30-239, Kraków, Poland.
The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland.
Sci Rep. 2023 Sep 25;13(1):16022. doi: 10.1038/s41598-023-43059-0.
Common buckwheat has a complicated flowering biology. It is characterized by a strong self-incompatibility resulting from heterostyly, i.e. the occurrence of two types of flowers: Pin and Thrum, differing in the length of pistils and stamens. Fertilization occurs only as a result of cross-pollination between these morphs. Suspicions exist that the disturbed ratio between plants producing Pin and Thrum flowers (with the latter type generating more seeds) causes low seed yield. The aim of the study was to analyze: (1) the ratio between plants with Pin and Thrum morphs, (2) flower and seed production, as well as abortion of flowers, (3) the composition of nectar collected at an early flowering stage and during full flowering. The study was performed under semi-controlled and field conditions on six Polish accessions. The results indicated that under semi-controlled conditions the Pin-to-Thrum ratio was indeed disproportionate; such a phenomenon is called anisoplethy. In the field, however, the Pin-to-Thrum ratio was well-balanced (isoplethy). The plants with both morphs aborted a similar percentage of flowers and produced a comparable number of empty seeds. The number of flowers, their abortion, and ripe seed production were independent of flower type, however, they were genotypically controlled. A strong correlation between the number of flowers produced by a plant, flower abortion and the number of empty seeds was found. The percentage of aborted flowers correlated positively with the weight of ripe seeds. Nectar composition was similar for all buckwheat genotypes, but we found some differences in the amount of individual sugars depending on the blooming stage. In the majority of accessions, the nectar produced at the early blooming stage was characterized by a greater mass and volume, and contained more individual sugars than at the full-flowering stage.
普通荞麦具有复杂的开花生物学特性。它的特点是自交不亲和性很强，这是由于异型花柱的存在，即出现两种类型的花：Pin 和 Thrum，它们在雌蕊和雄蕊的长度上有所不同。只有通过这些形态之间的异花授粉，才能受精。有人怀疑，Pin 和 Thrum 花的植株比例失调（后者产生更多的种子）会导致种子产量低。本研究的目的是分析：（1）产生 Pin 和 Thrum 形态的植株比例，（2）花和种子的产生，以及花的败育，（3）在早期开花阶段和完全开花阶段收集的花蜜的组成。该研究在半控制和田间条件下对六个波兰品种进行了研究。结果表明，在半控制条件下，Pin 与 Thrum 的比例确实不成比例；这种现象称为异型花柱。然而，在田间，Pin 与 Thrum 的比例是平衡的（同型花柱）。两种形态的植株都有相似比例的花朵败育，产生的空种子数量也相当。花的数量、败育和成熟种子的产生与花的类型无关，但受基因型控制。研究发现，植物产生的花的数量、花的败育和空种子的数量之间存在很强的相关性。败育花的百分比与成熟种子的重量呈正相关。荞麦的所有基因型的花蜜组成相似，但我们发现，由于开花阶段的不同，个别糖的含量存在一些差异。在大多数品种中，早期开花阶段产生的花蜜质量和体积较大，所含的个别糖也比完全开花阶段多。
