The reproductive success of flowering plants is strongly influenced by pollination mode, particularly in species exhibiting mixed mating systems. This study examined the effects of different pollination treatments on fruit set and seed production in Nigella damascena (Ranunculaceae) under field conditions over two consecutive growing seasons. Flowers were subjected to spontaneous self-pollination, induced self-pollination, geitonogamy, open pollination, induced cross-pollination, and supplemental cross-pollination. Pollination treatment significantly affected both fruit set and seed production, while year had no significant effect on either trait. N. damascena is capable of setting fruit and producing seeds via self-pollination; however, cross-pollination substantially increased both fruit set and seed number per follicular capsule. Notably, self-pollination treatments resulted in an approximately 47-57% reduction in seed set compared to cross-pollination. Although open pollination resulted in high fruit set, supplemental cross-pollination further increased seed number per follicular capsule, indicating pollen limitation of seed production rather than fruit initiation. These findings support a mixed mating system in N. damascena, in which partial self-compatibility provides reproductive assurance, while insect-mediated cross-pollination is essential for optimizing the pollen transition to maximize overall reproductive output.
Sprout regeneration post-logging is a pivotal process for the sustainable management of Cinnamomum camphora forests. However, the mechanical trauma incurred during logging can trigger physiological stress in plants, potentially impacting the regenerative vitality of the stumps. In the context of plant wound-response mechanisms, jasmonic acid (JA) plays a pivotal role in activating wound-induced systemic resistance, which is essential for enhancing the overall stress tolerance of the plant. Although the application of wound-healing agents is a common silvicultural practice to enhance regenerative vitality, the underlying molecular mechanisms—particularly the regulatory processes involving jasmonic acid (JA) signaling transduction—remain to be fully elucidated. This study investigated the physiological responses and root transcriptomic profiles of Cinnamomum camphora stumps under conditions of natural healing and wound-healing agent treatment. By comparing natural healing with wound-healing agent treatments, physiological analysis revealed a distinct responsive increase in root jasmonic acid (JA) levels during the early post-logging stage (5 d), reflecting the plant’s physiological defense regulation in response to initial trauma. Conversely, the application of wound-healing agents significantly attenuated JA levels, which was accompanied by a marked increase in sprout biomass and length. Transcriptomic analysis revealed that differentially expressed genes (DEGs) were significantly enriched in plant hormone signal transduction and MAPK signaling pathways. A total of 22 candidate genes involved in jasmonic acid (JA) biosynthesis were identified, among which CcAOS2 and CcOPR1 were significantly upregulated post-logging, suggesting their potential regulatory roles in early wound response. Our findings indicate that the wound-healing agent effectively buffers injury-induced JA fluctuations, thereby modulating the growth-defense trade-off. This study provides transcriptomic and physiological insights into the regenerative regulation of subtropical oil-seed forests after logging and offers a theoretical basis for tree damage management.
Terrestrial orchids harbor diverse endophytic fungi that produce bioactive compounds mimicking their hosts' metabolites, including alkaloids, flavonoids, and phenolics. These endophytes offer potential as dual-function biological agents that promote plant growth and suppress disease. This study aimed to isolate and evaluate endophytic fungi from terrestrial orchids for their ability to enhance plant growth and control Phytophthora capsici, a major pathogen in chili (Capsicum annuum). A total of 34 fungal isolates were obtained and screened for plant growth-promoting activity using Chinese cabbage (Brassica rapa var. pekinensis) on oatmeal agar. The three most effective isolates, i.e., SIG 10.2, GG 5.2, and GG 14.2, were further tested in vivo against P. capsici in chili plants. All three isolates significantly improved plant biomass and reduced disease symptoms, with SIG 10.2 showing the highest efficacy. Molecular identification revealed that the isolates belonged to Colletotrichum arxii (SIG 10.2), Colletotrichum gloeosporioides (GG 5.2), and Chaetomium globosum (GG 14.2). These results highlight the potential of orchid-derived endophytes as sustainable biofertilizers and biocontrol agents in horticultural crops.
Mineral fertilizers influence weed flora, but their effects are difficult to isolate due to agricultural practices and crop rotations. This study investigates weed community composition and structure under long-term mineral fertilization in an herbicide-managed winter wheat (Triticum aestivum L.) monoculture. The trial, established in 1896 in Gembloux, Belgium, includes NK, NP, NPK, PK, and Control treatments. Since 1975, winter wheat has been grown continuously. Weed flora was assessed through field surveys (realized flora) and seed bank analysis (potential flora) during the 2020-2021 study period. The realized flora (i.e. plant species present at the time of observation) surveyed before the first weeding operation comprised 12 species, with no significant effect of treatments on species richness. The dominant species were common to all treatments (Matricaria chamomilla, Pa-paver rhoeas, and Polygonum aviculare), with Equisetum arvense additionally dominant in the Control treatment. However, total weed density was higher in the Control and PK plots compared to the N-fertilized plots, likely due to reduced wheat growth and increased light availability allowing the development of both spring-and autumn-germinating species. Distinct community structures emerged, with the Control and PK plots having different and less nitrophilous communities than the N-fertilized plots. The potential flora (i.e. viable seeds and vegetative organs present on or in the soil) contained 30 species, with about 75% overlapping with the realized flora. Spring and summer germinators were present. Differences in community structure were less pronounced in the potential than in the realized flora. This study highlights that even in low-diversity, herbicide-managed fields, long-term chemical fertilizers impact weed density and composition, driven by species responding to nitrogen treatments. Long-term nutrient limitations, hindering crop growth, promote spring-germinating weed development, influencing community structure and density in winter wheat.
Applying plant growth regulators (PGRs) and plant architectural modifications could improve the production of various crops. This study aimed to examine the effects of PGRs and modifications of plant architecture on plant growth, insect infestations, chili pepper productivity, postharvest quality, and seed production. A split-split-plot experiment with a randomized block design was carried out from July 2022 to February 2023 in West Java, Indonesia. The main plot contained two crop densities (20,000 plants ha(-1) and 30,000 plants ha(-1)), the sub-plot contained two pruning applications (without pruning and with pruning), and the sub sub-plot contained five PGR applications (NAA (50 ppm), 2,4-D (5 ppm), Triacontanol (5 ppm), Ethephon (500 ppm), Tonic (1000 ppm) and no PGR application. The results showed that the plant architecture-PGR integration affected plant growth, yield, and yield characteristics, and insect infestation and prevented post-harvest weight loss. The pruning-treated crops grown at a population density of 20,000 plants/ha and treated with 5 ppm Triacontanol exhibited improved fruit quality. The pruned plants at both densities experienced lower damage by T. parvispinus and P. latus compared with the non-pruned plants. Bactrocera spp. fruit damage was also lower in the trimmed plants, although H. armigera damage was constant across the pruning treatments. The PGR treatment produced substantial variation in pest incidence. Triacontanol (5 ppm) resulted in the lowest infestation from T. parvispinus, P. latus, Bactrocera spp., and H. armigera. Combining plant architecture practices (population density and pruning) with plant growth regulators is an innovative and environmentally friendly way to improve chili pepper yields and can help meet the world's growing food needs.
