Mother Plant Research Articles

ТЕОРЕТИЧЕСКОЕ И ПРАКТИЧЕСКОЕ ОБОСНОВАНИЕ ВЫБОРА ПОДВОЯ ПРИ ВЕГЕТАТИВНОЙ РЕПРОДУКЦИИ ИНТРОДУЦЕНТОВ РОДА SYRINGA L. (OLEACEAE) В УСЛОВИЯХ ОРЕНБУРГСКОЙ ОБЛАСТИ

The proper selection of rootstock and graft combinations in lilac introducers, in order to take full advantage of grafting, requires a thorough understanding of the synergy of cultivar-rootstock combinations, as well as the identification of factors that may influence this process. The article analyzes the results of three grafting experiments using Syringa vulgaris L. and Syringa josikaea J. Jacq. ex Rchb. seedlings and vegetative rootstocks (rooted shoots) of Syringa vulgaris L. as rootstocks. The grafting material was the dormant buds of four highly ornamental cultivars of S. vulgaris L. – ‘Au- cubaefolia’, ‘Sensation’, ‘Marc Micheli’, ‘Congo’ and the late hybrid Syringa × prestoniae МсКelveу ‘Miss Canada’. It was found that the survival rate of cultivars on a particular rootstock may depend on the systematic affiliation of the mother plants of the cultivars. The best survival rate among all studied cultivars in the climatic conditions of the Orenburg region is achieved when using rooted vegetative shoots of S. vulgaris as a rootstock (over 90%), the worst – on the seed rootstock of S. josikea J. Jacq. ex Rchb. (up to 40%). The influence of the ambient temperature and humidity at the time of oculant fusion on the survival rate of grafts using S. vulgaris L. vegetative rootstock has been demonstrated (Wilcoxon T-test, statistical significance level p <<0.05). It is recommended to select the rootstock individually for each cultivar in order to achieve maximum survival rates of lilac cultivars in the climatic and geographical conditions of the Orenburg region and/or regions with similar conditions.

APPLICATION OF ETIOLATION OF GRAPE EXPLANTS IN VITRO CULTURE

Micropropagation of grapes is used to obtain original and certified planting material for planting mother plants. The decrease in the efficiency of microclonal reproduction is associated with difficulties at the stages of introducing explants into in vitro culture and rooting. The method of etiolation is simple to use and allows you to prevent phenolic oxidation of explants, has a positive effect on increasing the length of shoots and the number of roots. The purpose of the research was to determine the effectiveness of etiolation at the stages of introducing explants and rooting microcuttings in in vitro culture. The work was carried out in the laboratory of in vitro grape culture of the department of grape nursery, propagation and biotechnology of the National Scientific Centre «V.Ye. Tairov Institute of Viticulture and Winemaking» NAAS of Ukraine according to the generally accepted method on table, technical and grafted varieties of grapes. Etiolation was applied in two stages: introduction of initial grape explants into in vitro culture (for 7, 15, and 25 days) and rooting of grape microcuttings (for 7 and 15 days). The survival and proliferation of explants, the main biometric indicators of growth and development of microclones were determined. It was established that at the stage of introduction of initial explants of grapes into in vitro culture, the use of etiolation for 15 days, and at the stage of micropropagation - for 7 days, had a positive effect on rooting, proliferation of axillary buds and further development of explants and microcuttings. The height of the stem of the experimental microclones was 0.6-2.6 cm higher, and the number of leaves was 0.4-0.9 more than that of the control plants. Also, etiolation had a positive effect on the increase in the length and biomass of roots in microcuttings. In the future, it is planned to analyze changes in the in vitro reproduction coefficient of various grape varieties under the influence of etiolation.

Development of Recombinase Polymerase Amplification-Lateral Flow Dipstick (RPA-LFD) as a Rapid On-Site Detection Technique for Fusarium oxysporum.

Fusarium oxysporum can cause many important plant diseases worldwide, such as crown rot, wilt, and root rot. During the development of strawberry crown rot, this pathogenic fungus spreads from the mother plant to the strawberry seedling through the stolon, with obvious characteristics of latent infection. Therefore, the rapid and timely detection of F. oxysporum can significantly help achieve effective disease management. Here, we present a protocol for the recombinase polymerase amplification- lateral flow dipstick (RPA-LFD) detection technique for the rapid detection of F. oxysporum on strawberry, which only takes half an hour. A significant advantage of our RPA-LFD technique is the elimination of the involvement of professional teams and laboratories, which qualifies it for field detection. We test this protocol directly on plant samples with suspected infection by F. oxysporum in the field and greenhouse. It is worth noting that this protocol can quickly, sensitively, and specifically detect F. oxysporum in soils and plants including strawberry. Key features • This protocol is used to detect whether plants such as strawberry are infected with F. oxysporum. • This protocol has potential for application in portable nucleic acid detection. • It can complete the detection of samples in the field within 30 min.

Registration of ‘Espresso’ lowland switchgrass

Abstract‘Espresso’ (Reg. no. CV‐293, PI 687202) is a lowland ecotype (Gulf sub‐population) of switchgrass (Panicum virgatum L.) developed and released by Mississippi State University and the Mississippi Agricultural and Forestry Experiment Station. Espresso was developed from seven cycles of phenotypic recurrent selection for rapid seed germination without stratification. All cycles of selection were made using seed harvested from open‐pollinated isolation blocks containing approximately 100 mother plants. Germination was assessed in laboratory conditions for 15 years, culminating in 2 years of field‐based germination and emergence evaluation at five locations across Mississippi. Over a 2‐year period, germination and emergence of Espresso was significantly greater (P < 0.05) than seed from ‘Alamo’ and ‘Kanlow’. Field testing revealed Espresso as having significantly (P < 0.05) greater establishment success (mean number of seedlings per linear 30 cm) when compared to Alamo. Espresso was released based on the need for southeastern US‐adapted germplasm that possesses enhanced germination characteristics.

Assessment of Dormancy Level and Germination Ability of Seeds with Physiological Dormancy.

Germination test is fundamental and commonly used technique for seed dormancy and germination studies, and proper assessment of dormancy level and germination ability of a given set of seeds is prerequisite for most of the studies. However, germination is very sensitive to imbibition conditions, and dormancy development is also sensitive to growth conditions of the mother plants. In this chapter, we describe tips for plant growth and germination test mainly for physiological and molecular genetic studies with Arabidopsis. This protocol can be applied for other plant species with relatively small seeds and for various studies to analyze the effect of light, phytohormones, and other chemicals in seed germination.

Crearea plantației-mamă de categoria „Prebază” din genul V. Vinifera prin selecție fitosanitară

Phytosanitary selection is a means of eliminating diseased individuals with negative traits, preventing the spread of diseases, and selecting plants that are less susceptible to diseases, which greatly ensures the increase in productivity and quality of grape production. All stages of phytosanitary selection have been carried out: visual observation, biotype testing, sanitation of selected plants, multiplication through in vitro culture, growth and fortification of plants in greenhouse conditions, which allowed obtaining virus-free, phytoplasma-free and bacterial cancer-free grapevine clones from 14 mass and 19 technical varieties (phytosanitary clones). The results of biotype testing showed a widespread distribution of virotic diseases and bacterial cancer in asymptomatic form: Grapevine fleck (15–65%), Rhizobium vitis (26–44%), GLRaV-1 (8–26%), GLRaV-3 (7–39%). Of the biotypes with negative tests, 6 from native varieties, 6 from European varieties, 23 from new selections and 2 forms were selected. For the sanitation of the selected material after testing, thermotherapy was applied at to 51 oC for 45 min. Thanks to the in vitro method, 7 239 grapevine clones from native, European and new selection varieties were multiplied, with which the mother plantation of the nuclear stock was founded. Thus, the first step in the process of transferring viticulture from the Republic of Moldova based on certified planting material has been achieved.

Production of Benzyl Isothiocyanate from Moringa peregrina (Forssk.) Fiori via Suspension Cultures

Benzyl isothiocyanate (BITC) is one of the main constituents of Moringa peregrina, an endangered species in the flora of Egypt. The purpose of this study was to establish a procedure to enhance the in vitro production of BITC in Moringa peregrina suspension cultures. This could then aid in the mass production of this useful pure active compound and avoid the exploitation of natural resources of this valuable plant. Suspension cultures of Moringa peregrina was established from callus cells in liquid MS medium supplemented with 10.74 μM naphthalene acetic acid, 2.325 μM kinetin, in addition to salicylic acid as an elicitor and/or L-phenylalanine as a precursor of BITC. The combination of both salicylic acid and L-phenylalanine gave the highest accumulation of BITC after two weeks with 10.42-fold increase, compared to its content in the mother plant. This study is promising for the large-scale production of BITC, which has been identified as an anticancer agent with possible applications in the pharmaceutical industry. Plant Tissue Cult. & Biotech. 33(2): 85-95, 2023 (December)

Growth performance of cleft grafted velvet apple (Diospyros discolor Willd.)

Velvet apple is usually propagated through seeds but seeded plants do not maintain its true-to-type quality. The present work was undertaken to study the fate of cleft grafting of five selected velvet apple genotypes during 2018 - 2019 at the Germplasm Center, Patuakhali Science and Technology University. The pot experiment was conducted in RCBD with two factors as scions and Days after Grafting (DAG) consisting of 10 replications of the scions. Scions from five promising mother plants were considered as treatments (Dumki-Dd-S1, Dumki-Dd-S2, Dumki-Dd-S3, Dumki-Dd-S4 and Mirzaganj-Dd-S5) and were cleft grafted on seedling rootstock of Dumki-Dd-R1. At 84 DAG, significant differences were observed among the scion treatments regarding the studied growth parameters. The days required to bud break varied significantly which ranged from 14 days (Dumki-Dd-S4) to 18 days (Mirzagonj-Dd-S5). The maximum length (54.30 cm) and diameter (2.00 cm) of rootstock were recorded in Mirzagonj-Dd-S5 at 84 DAG. However, maximum scion length (22.20 cm) and scion diameter (0.70 cm) were noted in Dumki-Dd-S1at 84DAG. The highest graft heights of Dumki-Dd-S2 (71.20 cm) and Mirzaganj-Dd-S5(71.50 cm) were statistically similar at84 DAG. Graft success was highest in Mirzagonj-Dd-S5(60.00%) followed by Dumki-Dd-S4 (40.00%) at 84 DAG. The maximum number of sprouted shoots (2.10) was counted in Dumki-Dd-S1, however, the highest length and diameter of sprouted shoot (7.1 cm and 0.66 cm, respectively) and maximum number of leaf (7.40 per graft) were found in Mirzaganj-Dd-S5during the study period. It could be concluded that, Mirzaganj-Dd-S5 and Dumki-Dd-R1showed the best stionic relationship for multiplication of velvet apple by cleft grafting. South Asian J. Agric., Vol. 9, No.1&2, 2022-‘23: 1-10

Multiplication performance of monkey jack by cleft grafting on single source seedling rootstock

The present research work was undertaken to study the fate of cleft grafting of five potential monkey jack genotypes during 2020-2021 at the Germplasm Center, Patuakhali Science and Technology University, Bangladesh. Scions from five in situ conserved promising mother plants named as Dumki-Al-S1, Dumki-Al-S2, Dumki-Al-S3, Dumki-Al-S4 and Kalapara-Al-S5 were cleft grafted on seedling rootstock (Dumki-Al-R1) of single genotype. A pot experiment was set in two-factor (Scions and Days after grafting) RCBD with 10 replications. The time required to break bud varied significantly among the treatments and ranged from 14 to 20 days. Dumki-Al-S1 required the maximum time to bud break (20 days) followed by Dumki-Al-S3 (18 days). Dumki-Al-S2 took minimum time (14 days) for bud breaking. The maximum increased length of rootstock found in Dumki-Al-S2 which were 55.00, 55.70, 56.44 and 65.30 cm at 21, 42, 63 and 84 days after grafting (DAG), respectively, followed by Kalapara-Al-S5 (61.80, 54.80, 55.30, and 57.12 cm at 21, 42, 63 and 84 DAG, respectively). Kalapara-Al-S5 showed maximum diameter of rootstock (1.44, 1.70, 1.80 and 1.94 cm at 21, 42, 63 and 84 DAG, respectively) followed by Dumki-Al-S4 (1.08, 1.24, 1.34 and 1.42 cm at 21, 42, 63 and 84 DAG, respectively). The length and diameter of scion of Dumki-Al-S4 and Kalapara-Al-S5 were higher and statistically identical at 84 DAG. The maximum graft height was recorded in Kalapara-Al-S5 (70.60, 73.40, 76.00 and 77.10 cm at 21, 42, 63 and 84 DAG, which was statistically similar with Dumki-Al-S2. Kalapara-Al-S5, Dumki-Al-S3 and Dumki-Al-S4 showed maximum number of leaves per graft at 84 DAG. The maximum graft success of 40% was observed in both Dumki-Al-S1 and Dumki-Al-S3 at 84 DAG, whereas, other treatments had less than 20% graft success. Kalapara-Al-S5 and Dumki-Al-S2 showed significantly higher and identical number of sprouted shoots at 84 DAG. Dumki-Al-S1 showed the maximum lengths and diameters of shoot at 84 DAG. The overall performance of the stionic combinations indicated that Dumki-Al-S1 and Dumki-Al-S3 were found promising for further grafting trials with seedling rootstocks.

Identification of cocoa (Theobroma cacao L.) genetic uniformity through RAPD molecular markers.

Theobroma cacao L. has been propagated through either generative or vegetative techniques. One of the vegetative methods of propagating cocoa is somatic embryogenesis. Somatic embryogenesis has been employed by the Indonesian Coffee and Cocoa Research Institute for producing cocoa seedlings. Plant breeding activities are hampered by the significant level of plant heterogeneity among their progeny. Mislabelling of genetic impurities can be an issue. Molecular markers can be used to detect genetic variation at an early stage. The most common marker is the RAPD molecular marker. The study aims to determine the polymorphic RAPD primers in the analysis of genetic uniformity between mother plants and the seedlings derived from somatic embryogenesis (SE). The analyzed samples consisted of twelve individuals: six mother plants and six seedlings derived from SE. The results revealed that the percentage of polymorphic bands was 100% with band sizes ranging from 295-2785 bp for primer GY169 while for primer GY107 percentage of polymorphic bands was 80% with band sizes ranging from 345-1678 bp. Primer GY169 and primer GY107 can be amplified and used for cocoa similarity and heterogeneity.

Effect of indole butyric acid on the propagation of Hylocereus undatus "pitahaya" under greenhouse conditions

Hylocereus undatus "pitahaya", is a tropical species of cactus that has been established throughout Latin America. Its fruit is considered a potential nutraceutical food because it provides numerous beneficial antioxidant and probiotic properties for health. Reason for which its cultivation has increased both for the national and international market, one of the main limitations being the rapid propagation and establishment of the cuttings. Given this, it was proposed as a research objective to determine the effect of indole butyric acid on the propagation of Hylocereus undatus "pitahaya", as a promoter of root growth. In the greenhouse, stems of mother plants were used, which were subjected to different doses of IBA (0, 5000, 10000 mg/L). A completely randomized design was used, evaluating the longest root length, number of primary roots, root mass weight, root dry weight, stem weight and stem length. The data were analyzed using the software R version 4.1.2, showing the not existence of significant differences between the treatments. It is concluded that treatment 1, constituted by 0 mg/L of IBA, is the best, since a better response was evidenced in relation to the greater root length, number of primary roots and root mass weight, in the same way. for weight and stem length of H. undatus "pitahaya". Therefore, for its propagation the use of indole butyric acid is not essential.

To eat or not to eat: premature sprouting (vivipary) in cereal and fruit crops

Vivipary also known as the precocious germination of seeds while still attached to the mother plant or fruit, it’s a relatively common phenomenon in angiosperms. However, the proliferating seedlings though interesting to look at, deter customers from eating the fruits. Similarly, vivipary is an adverse phenomenon for the agroindustry because of the lowest quality and palatability of fruits as well as lower seed set and viability. This paper highlights the taxonomic occurrence of vivipary in cereal and crop plants and the detrimental effects of this phenomenon in agricultural crops. According to literature sources, there are 38 fruit crops in which vivipary has been reported. The families Cucurbitaceae, Poaceae, Rutaceae, and Solanaceae include the fruits with the highest incidence of vivipary in the markets.

The effect of the gibberellic acid on the morphogenesis of Hydrangea L.

Modern ornamental gardening is difficult to imagine without beautifully flowering shrubs. One of these is hydrangea. In Russia, culture is one of the most popular in decorative gardening. However, there are some difficulties in obtaining a large amount of planting material of new and highly ornamental varieties. Therefore, it is important to develop effective reproduction technologies of the studied culture. It is possible to obtain high-quality planting material by clonal micropropagation in a short period of time. The resulting plants grow similar to the mother plant. Hydrangea L. representatives are effectively cultivated in vitro. There are many results of research about micropropagation of hydrangea, but there is only isolated datas about the comparative assessment of the morphogenetic potential of various species of the Hydrangea L. depending on the concentration of growth regulators. There are many growth regulators in the practice of cultivation in vitro. 6-benzylaminopurine (6-BAP), gibberellic acid, kinetin, zeatin. Murashige (MS) and Skoog and Quoirin (QL), Lepoivre nutrient media are used to activate the growth of axillary buds at the stage of micro-reproduction proper. The effect of the use of gibberellins on the in vitro cultivation of hydrangeas is poorly studied. The research aimed to studing the effect of gibberellic acid on the regeneration of shoots of Hydrangea L. We study the effect of gibberellic acid (GA) – 0.5 and 1 mg/l of concentrations. Reproduction coefficient of the Hydrangea macrophylla Thunb. (H. macrophylla) was 12.0, when we used 1 mg / l GA. The length of the Hydrangea paniculata Siebold (H. paniculata) micro-shoots increased by 25 % when we used 1 mg/l GA. According to the research of 2020, the best results on the use of different nutrient mediums mineral bases were obtained during in vitro cultivation on a QL nutrient medium with the addition of 0.3 mg/l 6-BAP. In the future this nutrient medium was as a control. After the application of GA, regenerants were planted to adapt of phytotron conditions. The best survival rate of H. macrophylla (90 %) (var. Peppermint) was recorded after cultivation of a nutrient medium containing 1 mg/l GA. The adaptability of ‘Magical Candle’ was excellent regardless of GA concentration.

Bacteria existing in pre-pollinated styles (silks) can defend the exposed male gamete fertilization channel of maize against an environmental Fusarium pathogen.

In flowering plants, fertilization requires exposing maternal style channels to the external environment to capture pollen and transmit its resident sperm nuclei to eggs. This results in progeny seed. However, environmental fungal pathogens invade developing seeds through the style. We hypothesized that prior to environmental exposure, style tissue already possesses bacteria that can protect styles and seed from such pathogens. We further hypothesized that farmers have been inadvertently selecting immature styles over many generations to have such bacteria. We tested these hypotheses in maize, a wind-pollinated crop, which has unusually long styles (silks) that are invaded by the economically-important fungal pathogen Fusarium graminearum (Fg). Here, unpollinated silk-associated bacteria were cultured from a wild teosinte ancestor of maize and diverse maize landraces selected by indigenous farmers across the Americas, grown in a common Canadian field for one season. The bacteria were taxonomically classified using 16S rRNA sequencing. In total, 201 bacteria were cultured, spanning 29 genera, 63 species, and 62 unique OTUs, dominated by Pseudomonas, Pantoea and Microbacterium. These bacteria were tested for their ability to suppress Fg in vitro which identified 10 strains belonging to 6 species: Rouxiella badensis, Pantoea ananatis, Pantoea dispersa, Pseudomonas koreensis, Rahnella aquatilis, and Ewingella americana. Two anti-Fg strains were sprayed onto silks before/after Fg inoculation, resulting in ≤90% reductions in disease (Gibberella ear rot) and 70-100% reductions in associated mycotoxins (deoxynivalenol and zearalenone) in progeny seeds. These strains also protected progeny seeds post-harvest. Confocal fluorescent imaging showed that one silk bacterium (Rouxiella AS112) colonized susceptible entry points of Fg on living silks including stigmatic trichomes, wounds, and epidermal surfaces where they formed thick biofilms. Post-infection, AS112 was associated with masses of dead Fg hyphae. These results suggest that the maize style (silk) is endowed with potent bacteria from the mother plant to protect itself and progeny from Fusarium. The evidence suggests this trait may have been selected by specific indigenous peoples, though this interpretation requires further study.

A classification system for seed (diaspore) monomorphism and heteromorphism in angiosperms

Abstract‘Seed heteromorphism’ is a broadly- and loosely-defined term used to describe differences in size/mass, morphology, position on mother plants and ecological function (e.g. dispersal, dormancy/germination) of two or more seeds or other diaspores produced by an individual plant. The primary aim of this review paper was to characterize via an in-depth classification scheme the physical structural design (‘architecture’) of diaspore monomorphism and diaspore heteromorphism in angiosperms. The diaspore classification schemes of Mandák and Barker were expanded/modified, and in doing so some of the terminology that Zohary, Ellner and Shmida, and van der Pijl used for describing diaspore dispersal were incorporated into our system. Based on their (relative) size, morphology and position on the mother plant, diaspores of angiosperms were divided into two divisions and each of these into several successively lower hierarchical layers. Thus, our classification scheme, an earlier version of which was published in the second edition of ‘Seeds’ by Baskin and Baskin, includes not only heteromorphic but also monomorphic diaspores, the Division to which the diaspores of the vast majority of angiosperms belong. The scheme will be useful in describing the ecology, biogeography and evolution of seed heteromorphism in flowering plants.

Effect of 2,4-D and NAA in Callus Induction and Differentiation from Different Explants of Moringa Oleifera Lam

This study was carry out in the Laboratory of Plant Cells and Tissue Culture / Department of Forestry Sciences in the College of Agriculture and Forestry / University of Mosul during the year 2021-2022 to study the effect of adding different concentrations of 2,4-Dichloro-Phenoxyacetic acid (2,4-D) or Naphthalene Acetic Acid (NAA) to the MS medium in the induction of callus from different parts of the Moringa oleifera Lam. and then study the effect of different concentrations of 6-Benzyladenine (BA) and Kinetin (Kin) on the differentiation of callus into buds and embryogenesis. Concerning callus induction, the results showed that 2,4-D or NAA in the nutrient medium was necessary after three weeks of cultivation 2,4-D was superior to NAA in the percentage of callus induction, as callus induction occurred by 100% of the explants cultured in the media supplemented with 0.1 mg.l−1 2,4-D. On the other hand, the parts (apical buds, single node, parts of the leaf blade, epicotyl, cotyledon, hypocotyl) differed significantly among themselves in the percentage of their ability on callus induction, as the cotyledons gave the highest rate of induction, amounting to 80%. The shoots resulting from the callus rooted after four weeks of cultivation in media supplemented with different concentrations of IBA at a rate of 100%, regardless of the concentration of IBA. The study proved the existence of a genetic match between the mother plants and the plants produced from the callus induction from them.

Evaluation of phenotypic variability of seedlings obtained from open pollination of three varieties of the genus Hylotelephium

ABSTRACT This article reflects on the conventional open pollination breeding method of the genus Hylotelephium. Six-year-old seedlings were evaluated and compared with the mother plants for 3 years. A total of 1 063 seedlings were evaluated (54 in the H. ‘Red Cauli’, 90 descendants in the H. ‘Xenox’, 919 descendants in the H. ‘Purple Emperor’). This study deals with six evaluated characters of vegetative parts of plants (habit, height and width of plants, length and width of leaves and the colour of the upper side of the leaves). The most significant phenotypic variability was confirmed for habit, plant height, leaf colour in summer and leaf length in population H. ‘Xenox’ and for spring colouration of lower leaves in population H. ‘Red Cauli’. The highest degree of variability was found for plant height, where the monitored populations split into a total of seven different sizes. On the contrary, the lowest degree of variability was demonstrated for the length and width of leaves, where all populations showed shorter and narrower leaves compared to the mother plants, with minimal differences.

Effect of Spraying Mother Plant with the Seaweed Extract and Nano-magnesium on Seed Germination and Seedling Vigor of Maize

Effect of Spraying Mother Plant with the Seaweed Extract and Nano-magnesium on Seed Germination and Seedling Vigor of Maize

Genetic mining of desirable alleles for transgenerational stress memory through enhancing drought adaptation in wheat

Plant memory refers to the phenomenon where past environmental experiences influence the responses of plants to current/future events. Drought stress has a mostly significant negative impact on wheat, which is a vital crop for global food security. In the context of germination, plant memory can manifest as 'transgenerational priming', where mother plants exposure to drought stress alters the germination behavior of the next-generation seeds. Therefore, our study aimed to explore the genetic factors underpinning transgenerational drought tolerance in wheat using a diverse collection of 111 by the Genome-Wide Association Study (GWAS). In the seed germination test, all genotypes had higher Germination Percentage (G%) and Germination Pace (GP) from seeds of Stressed Plants (OSP) than those of Non-Stressed Plants (ONP) by 16% and 29%, respectively), indicating that Transgenerational Stress Memory (TSM) may manifest through appearing to possess a more persistent stress memory. For root length, OSP had a greater Root Length (RL) than ONP by 45%, suggesting a more highly developed root system in the OSP seeds. The time at which TSM manifests during the plant life cycle could reflect disparate strategies of TSM duration among genotypes from OSP and ONP. Genetic associations of TSM showed highly significant QTNs for all of the studied traits. For instance, a highly significant QTN (BS00068042_51) located on chromosome 2B at position 107,381,860 bp inside the gene TraesCS2B02G140800 encodes Cytochrome P450 (CYPs) that was found to be associated with the traits of FW and SMC for OSP. CYPs play a significant role in wheat response to environmental stresses. Therefore, further research into the specific alleles/candidate genes and their functions in wheat transgenerational stress memory will provide valuable insights for developing strategies to enhance drought tolerance in wheat crops through genetic manipulation or targeted interventions.

Symptomology, prevalence, and impact of Hop latent viroid on greenhouse-grown cannabis (Cannabis sativa L.) plants in Canada

The incidence of Hop latent viroid (HLVd) affecting cannabis plants in licenced production facilities in Canada during 2020–2023 was determined by RT-PCR analyses of 15 947 samples from nine provinces. Positive detection ranged from 5.3% to 92% of samples submitted, depending on province and year of sampling. The average country-wide HLVd infection incidence was 25.6%. Symptoms on affected plants varied with plant growth stage, and ranged from asymptomatic to mild leaf curl and mottling on stock (mother) plants and on vegetative plants, to extreme stunting and reduced inflorescence development on flowering plants. All symptomatic and some asymptomatic plants contained a 256 nucleotide RNA fragment with 100% sequence homology to HLVd from GenBank. The viroid was detected in various tissues of stock, vegetative, and flowering plants, including the uppermost leaves, at middle and lower positions in the canopy, and in the roots. The incidence of infection varied with the cannabis genotype. Flowering plants displayed yellowing or darkening of inflorescence leaves surrounding the pistillate flowers. Reductions of 12–42% in inflorescence stem lengths, fresh weights, and plant heights were observed in infected plants compared to noninfected plants, depending on the genotype. Levels of tetrahydrocannabinol (THC) and terpenes in diseased inflorescences were also significantly lower. The development of glandular trichomes which produce and store cannabinoids and terpenes was greatly reduced by HLVd infection. The affected trichomes had shorter stalk lengths and smaller glandular head sizes, and appeared shrivelled upon drying of the inflorescences. Hop latent viroid poses a significant economic threat to the cannabis industry.