Sedum dormiens (Crassulaceae, Sempervivoideae, Sedeae): a new species from the Sierra de Manantlán, Mexico

Sedum dormiens (Crassulaceae) from the Sierra de Manantlán in Jalisco, Mexico, is described. The distinctive characters of the species are its chamaephytic nature, capillary roots, formation of large colonies, tetramerous flowers with white petals, dormant terminal and lateral buds in the mother plant and connate fruits of ½–¾ its length. The habitat and morphology of the species is illustrated and its relationships with close species presented. Its conservation status was categorized as Endangered (EN).

Changes in the growth and reproduction of a clonal plant as a result of disruption of mycorrhizal network

In a clonal network, a mother plant is connected with daughter ramets. During network development, new ramets may encounter barriers that disrupt network integrity. As a result, resource allocation within a network is disturbed. In this study, the effect of network integrity disruption on the size of ramets and their sexual reproduction was investigated in mouse-ear hawkweed (Hieracium pilosella). Three types of networks were formed experimentally with unlimited resource allocation, with limited resource allocation between a mother plant and its daughter ramets and with limited resource allocation between all ramets. Networks were either supported by the presence of a mycorrhizal fungus or restricted by its absence. We found that the size of the mother and the effectiveness of sexual reproduction did not differ among network types. The length and dry mass of runners were higher in cases with limited resource exchange between a mother plant and its daughters. In the clonal plant network without any barriers to connection, a higher number of rosettes and lower dry mass of daughters were recorded. The mean number of daughter flowers did not differ among the network types. Mycorrhizal network is one of the most important factors for the sexual reproduction of clonal plants. With a reduced mycorrhizal network, plants invested in clonal growth.

Collection of the genus Cotinus Mill. in the National dendrological park “Sofiyivka” of NAS of Ukraine

Intr0ducti0n. Green plantations in Ukraine require optimization of species, shape and varietal composition of ornamental plants. These include the genus Cotinus Mill. one of the oldest genera of angiosperms of the Sumac family (Anacardiaceae Lindl.). Matcrials and mcth0ds. The species and varietal composition of the Cotinus collection of the Sofiyivka National Dendrological Park of the National Academy of Sciences of Ukraine was studied. Morphological fea- tures of collectibles of the genus Cotinus were studied according to generally accepted methods. Rcsults and discussi0n. In he collection of the National Arboretum “Sofiyivka” of the National Academy of Sciences of Ukraine two species and 4 cultivars of the genus Cotinus were tested and studied, namely: C. obovatus Raf., C. coggygria Scop., C. coggygria ‘Royal Purple’, C. coggygria ‘Purpureus’, C. coggygria ‘Young Lady, C. coggygria ‘Golden Spirit’. According to our research, all members of the genus Cotinus winter-, frost-resistant, as well as drought-resistant plants. They have satisfactory growth and bloom and bear fruit annually. C0nclusi0ns. Thus, the collection of plants of NDP “Sofiyivka” includes a valuable fund of genetic resources of the genus Cotinus, which is used mainly as a mother plant for the reproduction of ornamental forms that are in demand in the market of seedlings.

Cryopreservation of Hazelnut (Corylus avellana L.) Axillary Buds from In Vitro Shoots Using the Droplet Vitrification Method

Cryopreservation by droplet vitrification was applied to hazelnut (Corylus avellana L.). axillary buds of the Italian cultivated variety Tonda Gentile Romana, which were collected from in vitro growing shoots, immersed in ice cooled PVS2 or PVS3 for 60 or 90 min, then transferred to a droplet of vitrification solution, placed on a strip of aluminium foil, and plunged into liquid nitrogen (LN). Additionally, the effect on the recovery of the mother plant after cryopreservation was evaluated, following a cold pre-treatment at 4 °C for 3 months. The highest regrowth percentage (56.7%) was obtained after applying PVS3 for 60 min, while the application of PVS2 for the same amount of time reduced regrowth to 41.5%. Increasing the exposure to vitrification solutions to 90 min reduced regrowth to 43.3% when PVS3 was applied, and 35.6% if PVS2 was used. The cold pre-treatment on the mother plant did not significantly improve overall regrowth. The cryopreservation process did not decline the rooting ability of the recovered shoots.

Spread of Xanthomonas vasicola pv. musacearum within banana mats: implications for Xanthomonas wilt management

Xanthomonas wilt (XW) of banana caused by Xanthomonas vasicola pv. musacearum (Xvm) does not spread to all plants physically interconnected through the rhizome when one or a few are diseased. However, the factors behind this incomplete systemic spread of Xvm are not fully known yet could inform XW management. This study explored the effect of Xvm inoculum amounts, number and size of suckers, sucker positioning on mother plant corms and other mother plant corm attributes on sucker colonization. A shorter (p <0.05) incubation period (17.9 vs 21.1 days) and higher (p<.001) cumulative number of symptomatic leaves (5.2 vs 1.6 leaves) was observed when all (high inoculum) compared to two leaves (low inoculum) were inoculated. Xvm was recovered in corms at 29 days post inoculation (dpi) in both treatments with no differences (p >0.05) in proportions of corms with Xvm between the treatments. However, Xvm was recovered earlier and at a higher frequency in suckers when all leaves were inoculated. Lower Xvm recoveries occurred in the lower corm sections to which most suckers were attached relative to the middle and upper corm sections. Xvm incidence in corms increased with the number of attached maiden suckers, and the dpi while it declined with increasing mother plant and corm height. Thus, Xvm spread within mats is influenced by the amount of inoculum and the physiological stage (e.g., height) of the plant and attached suckers. The position of suckers, predominantly at the bottom of corms also protects them from infection. Measures that reduce Xvm inoculum build-up in mats are thus crucial for minimizing within mat XW spread.

The analysis of the suitability of using waste from the production of planting material for apple trees to obtain natural anthocyanin dyes

The analysis of the content of pigments in the stems of clonal apple rootstocks bred by Michurinsky State Agrarian University showed a high content of anthocyanins (more than 200 mg/100 g for rootstock 54-118). When determining the qualitative composition, it was revealed that anthocyanins in the stems of the rootstocks are represented by three groups, while there are differences in the shape of the rootstocks. As a source of pigment production, it is necessary to select rootstocks with a high endogenous synthesis of anthocyanins (i.e. red-leaved forms 54-118, 57-491, 98-7-77, etc.), during the cultivation of which, in addition to the main product—detachable rooted cuttings-one can additionally receive from 3 to 10 kg of anthocyanin dyes from 1 hectare of mother plant.

Effect of Grafting Dates on Success and Growth of Kumquat (Fortunella japonica Swingle) Sapling

An experiment was carried out to study the effect of grafting dates on the success and growth of kumquat sapling during 2017-18 at Banepa, Kavre to standardize suitable grafting time. The experiment was conducted in a single factor completely randomized design with five treatments and three replications. The treatments consisted of five grafting dates which viz., 25th November, 10th December, 25th December, 10th January and 25th January. Scion collected from the mother plant of kumquat was grafted onto two years old trifoliate orange rootstock by side veneer method at 15 days intervals under screen house. The data were recorded at every 30 days interval and found a significant effect of grafting dates on most of the economically important parameters such as graft success percent, the mortality of sprouted grafts, sapling height, number of leaves per sapling and leaf area. The result revealed that 100% graft success was observed on the grafts prepared in January. The highest mortality (13.68±0.58%) was reported on 25th November grafted sapling. The sapling height (39.68±3.68 cm), number of leaves per sapling (23.12±3.43) and leaf area (16.34±1.05 cm2) were found superior for 10th January grafted sapling while the number of primary and secondary branches per sapling were found non-significant for all grafting dates. Therefore, the study revealed that 10th January was the most suitable time for grafting of kumquat under Kavre, Nepal conditions.

Screening of Mango Landraces for Polyembryony and Confirmation of Seedling Origin using Microsatellite Markers

Background: The introduction of polyembryonic rootstocks in the area of propagation is of great importance since they produce one zygotic and several nucellar plantlets. Proper identification of sexual embryo from each hybrid seed is necessary in order to preserve only the nucellar seedlings, which would help to maintain the rootstock’s genetic characteristics as well as to overcome the major constraints in the area of fruit breeding especially in hybridization programme by eliminating the nucellar ones to advanced generations. Contrasting reports exists regarding the vigour of zygotic seedlings of polyembryonic mango genotypes. It is necessary to identify/ distinguish the zygotic seedling from the nucellar population at an early stage, for which, microsatellite analysis could be a reliable tool. Methods: The experiment was laid out in completely randomized design (CRD) with 20 treatments replicated thrice. The twenty local mango landraces from Thiruvananthapuram (Kerala) were screened for polyembryony and were geo-referenced. Germination studies were conducted. Microsatellite analysis of all the plantlets from two varieties which exhibited the highest polyembryony were done using SSR primers and their banding patterns were compared with those of their respective mother plants. Result: Out of twenty mango varieties screened, seventeen were polyembryonic. Kappa Manga recorded the highest germination, germination index and seedling vigour index-I. Kotookonam Varikka recorded the highest polyembryony and followed by Kochu Kilichundan. Microsatellite analysis revealed that all the seedlings obtained from the respective stones of Kotookonam Varikka and Kochu Kilichundan had identical SSR profile to the mother plant, which indicated nucellar origin of seedlings having similar genetic composition to the mother plant.

Rooting of Wild Blueberry (Vaccinium spp.) Cuttings From the Peruvian Northeast

The objective of this study was to evaluate the effect of indole-3-butyric acid (IBA) on the rooting of five wild accessions of blueberry (HCHA-262, HCHA-271, HCHA-283, HCHA-286, and HCHA-290) obtained from natural populations in the province of Chachapoyas (northern Peru). Buds were collected from the middle third of the plant and treated with IBA at concentrations of 0, 1,000, 2,000, and 3,000 mg L −1 . The results indicated that of the IBA doses, the 2,000-mg L −1 dose achieved the best effects on the rooting percentage and the lengths and numbers of roots and shoots of each accession studied. Accessions HCHA-262 and HCHA-283 showed greater regeneration of new seedlings than the other accessions after 45 days. The rhizogenic capacity of the cuttings varied because of the influences of both the IBA concentration and the genotype of the mother plant.