Gleditsia saxatilis (Fabaceae), a new species from limestone areas of Guangxi, China based on morphological and molecular evidence

Gleditsia saxatilis Z.C.Lu, Y.S.Huang & Yan Liu, a new species was found from limestone areas of Guangxi, China. The morphological and phylogenetic analyses showed that G. saxatilis is similar to G. sinensis, but differs by its habit indeciduous, winter buds globose or subglobose, apex round, petiolules glabrescent to glabrous, leaflets 2–4 pairs, leathery, both sides glabrous, racemes shorter, 2.5–7 cm long, ovary glabrous, legume slightly falcate, stipe 3–8 mm long.

Periodic events of Potamogeton alpinus in NW Poland (Pomerania region)

We have determined the timing of periodic events, such as leaf formation, flowering, fruiting and wintering of the aquatic plant Potamogeton alpinus. This study was performed in 15 watercourses situated in NW Poland in 2014–2015. Characteristics of the age stages were determined on the basis of 728 modules and phenological data were collected from permanent plots. In the study area, the plant appeared in week 12 of the calendar year, when water temperature in the streams was 5.4 ± 0.16°C. At that time, the first leafy juvenile shoots developed from winter buds. In week 22 (water temperature 13.9 ± 0.85°C), juvenile shoots became mature, whereas the first flowers were formed in week 24 (15.6 ± 1.04°C). The generative phase lasted twelve weeks with water temperature from 15.6 ± 1.04°C to 18.9 ± 3.23°C. Between weeks 37 and 44 (water temperature from 13.7 ± 0.77°C to 6.3 ± 1.05°C), senile shoots dominated in the population. From week 45 until week 11 of the next year (water temperature < 5.4 ± 0.16°C), the plants were in the winter resting stage. In our view, climate warming might disturb the phenology of P. alpinus, decreasing the probability of sexual reproduction of the species and the phenological distance between the Central European Plain and the Scandinavian populations.

The Effects of the Summer Pruning Operations on the Winter Buds Productivity of cv. Vranec (Vitis vinifera L.)

The study presents the analysis of the influence of summer pruning operations (defoliation, cluster thinning) on the parameters of a potential productivity of winter buds at the vine variety Vranec grown near Veles in the period 2013-2015. For this research, four treatments were set: control, defoliation and two types of cluster thinning: 10 and 6 clusters per vine. From the obtained results it is found that there are no injuries in the main winter buds during the vegetation period and the potential fruitfulness is determined by higher coefficient, 1.38, which depends on the location along the cane. The yield at this variety will be formed mainly by clusters with size of 350-550 μm, followed by those with the length of 550-750 μm. The application of defoliation and regulation of the vine yield has a beneficial effect on increasing the rate of potential fruitfulness of winter buds, the number of buds with 2 and 3 clusters, increasing the inflorescences with a length of 350-550 μm and the appearance of those longer than 750 μm.

Stilbenes in the different organs of Vitis vinifera cv. Merlot grafted on Teleki Kober 5BB rootstock

<p style="text-align: justify;"><span style="font-size: medium;"><strong>Aim: </strong>To determine which of the grapevine organ is the richest in stilbene, like the t-piceid, t-resveratrol and ε-viniferin and would it be useful as by-product of viticulture for processing stilbene concentrate.</span></p><p style="text-align: justify;"><span style="font-size: medium;"><strong>Methods and results: </strong>Nine organs, such as cane, buds, shoot tips, inflorescences, clusters at veraison, matured berry skins, seeds and cluster stems, of Merlot grafted on Teleki Kober 5BB rootstock were collected during a year and its ethanolic extractions were analyzed via HPLC-FLD. Stilbene content of the different organs occurred in a wide range, the lowest was 3.15 mg/kg dry weight (dw) measured in the seeds and the highest 2265 mg/kg dw in the buds.</span></p><p style="text-align: justify;"><span style="font-size: medium;"><strong>Conclusion:</strong> The present research demonstrated that different grapevine organs contain different amount of stilbene in the vineyard. The winter-buds, the roots and the matured cane internodes of Merlot are significantly richer in t-resveratrol and t-ε-viniferin than the green vegetative and generative parts we examined in one growing year. </span></p><p style="text-align: justify;"><span style="font-size: medium;"><strong>Significance and impact of the study: </strong>According to our knowledge there was no stilbenes measuring in several plant organs of a vine cultivar in field study, in vineyard. Our research pointed out the pruned cane could be primary source of stilbene of the health-industry. Beside that grape root is a by-product of grapevine nursery is also rich in stilbene. </span></p>

Insights into kiwifruit bud rot

Bud rot caused by Pseudomonas syringae pv. actinidiae biovar 3 (Psa) is a severe issue for the kiwifruit industry in New Zealand, particularly within green-fleshed cultivars. Successful management of this disease requires a detailed understanding of the disease cycle, such as identifying when and where Psa is present in/on winter- and flower-buds, the timing of bud-rot initiation, incidence and progression, and any varietal/seasonal/environmental differences. Relevant data is being collected on two green-fleshed cultivars: Actinidia chinensis var. deliciosa ‘Hayward’ and A. chinensis var. chinensis x A. chinensis var. deliciosa ‘Zesh004’ (commonly known as Green14), at four sites where bud rot had been noticed previously. Winter buds are sampled fortnightly and flower buds are sampled weekly from each site. Results from the first year, 2016, indicate that bud-rot incidence was higher in ‘Hayward’ than in Green14. Psa was detected in dormant and sprouted winter buds but its presence was inconsistent. Psa was detected in all parts of dissected ower buds, with the highest incidence in sepals, then in stalks, and gradually lower detection rates in petals, anthers and ovaries respectively.