Compact wavemeter incorporating femtosecond laser-induced surface nanostructures enabled by deep learning.

Miniature spectrometers have the advantage of high portability and integration, making them quick and easy to use in various working environments. The speckle patterns produced by light scattering through a disordered medium are highly sensitive to wavelength changes and can be used to design high-precision wavemeters and spectrometers. In this study, we used a self-organized, femtosecond laser-prepared nanostructure with a characteristic size of approximately 30-50 nm on a sapphire surface as a scattering medium to effectively induce spectral dispersion. By leveraging this random scattering structure, we successfully designed a compact scattering wavelength meter with efficient scattering properties. The collected speckle patterns were identified and classified using a neural network, and the variation of speckle patterns with wavelength was accurately extracted, achieving a measurement accuracy of 10 pm in multiple wavelength ranges. The system can effectively suppress instrument and environmental noise with high robustness. This work paves the way for the development of compact high-precision wavemeters.

An exotic plant successfully invaded as a passenger driven by light availability.

Invasive exotic plant species (IEPs) are widely distributed across the globe, but whether IEPs are drivers or passengers of habitat change in the invaded spaces remains unclear. Here, we carried out a vegetation and soil survey in 2018 and two independent field experiments (Pedicularis kansuensis removal in 2014 and 2015, and fertilization experiment since 2012) and found that the invasive annual P. kansuensis was at a disadvantage in light competition compared with perennial native grasses, but the successful invasion of P. kansuensis was due to the sufficient light resources provided by the reduced coverage of the native species. Conversely, nitrogen enrichment can effectively inhibit P. kansuensis invasion by increasing the photocompetitive advantage of the native species. sP. kansuensis invasion did not reduce species richness, but did increase plant community coverage, productivity and soil nutrients. Furthermore, the removal of P. kansuensis had little effect on the plant community structure and soil properties. Our results suggest that the passenger model perfectly explains the benign invasive mechanism of P. kansuensis. The invasion "ticket" of P. kansuensis is a spare ecological niche for light resources released by overgrazing.

A Legume Host Benefits More from Arbuscular Mycorrhizal Fungi Than a Grass Host in the Presence of a Root Hemiparasitic Plant.

In nature, most plants parasitized by root hemiparasites are also colonized by mutualistic arbuscular mycorrhizal (AM) fungi, highlighting the prevalence of this tripartite interaction. AM colonization is generally found to improve the growth of parasitized legumes but has little impact on grass hosts parasitized by root hemiparasites, and the underlying mechanisms are still unclear. In this study, we conducted a pot experiment to test the influence of AM fungus (Glomus mosseae) on the growth and photosynthesis of leguminous Trifolium repens and gramineous Elymus nutans in the presence of a root hemiparasitic plant (Pedicularis kansuensis). The results showed that inoculation with AM fungi significantly improved the growth performance of parasitized legumes via enhancing their nutrient status and photosynthetic capacity, even though a larger P. kansuensis parasitized the legume host in the AM treatment. In contrast, AM colonization slightly improved the shoot DW of grass hosts by suppressing haustoria formation and the growth of P. kansuensis. Our results demonstrated that legume hosts benefit more from AM inoculation than grass hosts in the presence of hemiparasitic plants, and set out the various mechanisms. This study provides new clues for parsing the tritrophic interaction of AM fungi, parasitic plants, and host plants.

A neglected alliance in battles against parasitic plants: arbuscular mycorrhizal and rhizobial symbioses alleviate damage to a legume host by root hemiparasitic Pedicularis species.

Despite their ubiquitous distribution and significant ecological roles, soil microorganisms have long been neglected in investigations addressing parasitic plant-host interactions. Because nutrient deprivation is a primary cause of host damage by parasitic plants, we hypothesized that beneficial soil microorganisms conferring nutrient benefits to parasitized hosts may play important roles in alleviating damage. We conducted a pot cultivation experiment to test the inoculation effect of an arbuscular mycorrhizal fungus (Glomus mosseae), a rhizobium (Rhizobium leguminosarum) and their interactive effects, on alleviation of damage to a legume host (Trifolium repens) by two root hemiparasitic plants with different nutrient requirements (N-demanding Pedicularis rex and P-demanding P. tricolor). Strong interactive effects between inoculation regimes and hemiparasite identity were observed. The relative benefits of microbial inoculation were related to hemiparasite nutrient requirements. Dual inoculation with the rhizobium strongly enhanced promotional arbuscular mycorrhizal effects on hosts parasitized by P. rex, but reduced the arbuscular mycorrhizal promotion on hosts parasitized by P. tricolor. Our results demonstrate substantial contribution of arbuscular mycorrhizal and rhizobial symbioses to alleviating damage to the legume host by root hemiparasites, and suggest that soil microorganisms are critical factors regulating host-parasite interactions and should be taken into account in future studies.

N-P fertilization did not reduce AMF abundance or diversity but alter AMF composition in an alpine grassland infested by a root hemiparasitic plant.

Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi (AMF) and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites remain untested. In view of the contrasting nutritional effects of AMF and root hemiparasites on host plants, we tested the hypothesis that fertilization may not show strong suppressive effects on AMF when a plant community was infested by abundant hemiparasitic plants. Plants and soil samples were collected from experimental field plots in Bayanbulak Grassland, where N and P fertilizers had been applied for three continuous years for control against a spreading root hemiparasite, Pedicularis kansuensis. Shoot and root biomass of each plant functional group were determined. Root AMF colonization levels, soil spore abundance, and extraradical hyphae length density were measured for three soil depths (0-10 cm, 10-20 cm, 20-30 cm). Partial 18S rRNA gene sequencing was used to detect AMF diversity and community composition. In addition, we analyzed the relationship between relative abundance of different AMF genera and environmental factors using Spearman's correlation method. In contrast to suppressive effects reported by many previous studies, fertilization showed no significant effects on AMF root colonization or AMF species diversity in the soil. Instead, a marked increase in soil spore abundance and extraradical hyphae length density were observed. However, fertilization altered relative abundance and AMF composition in the soil. Our results support the hypothesis that fertilization does not significantly influence the abundance and diversity of AMF in a plant community infested by P. kansuensis.

Fast and abundant in vitro spontaneous haustorium formation in root hemiparasitic plant Pedicularis kansuensis Maxim. (Orobanchaceae).

Haustorium formation is the characteristic feature of all parasitic plants and a vital process for successful parasitism. Previous investigations on haustorium initiation and development are constricted to induced processes by host-derived signals or synthetic analogs. Spontaneous haustorium formation in the absence of host signals, a process representing an early stage in the evolution of parasitic plants, remains largely unexplored. Lack of fast and frequent formation of spontaneous haustoria greatly hinders full understanding of haustorium formation in root hemiparasites. In this study, seedlings of Pedicularis kansuensis Maxim., a facultative root hemiparasitic species in Orobanchaceae observed to produce many spontaneous haustoria, were grown in autoclaved water agar in the absence of any known haustorium-inducing stimulants. We aimed to test the temporal and developmental pattern of spontaneous haustorium formation. Also, effects of sucrose supply and root contact on spontaneous haustorium formation were tested. Spontaneous haustoria were observed starting from six days after germination, much earlier than previously reported root hemiparasites. A majority of the spontaneous haustoria formed on lateral roots. Percentage of seedlings with spontaneous haustoria was 28.8% when grown on water agar plates, with a mean of four haustoria per seedling two weeks after germination. Haustorium formation by seedlings grown in water agar amended with 2% sucrose was more than twice of those without sucrose amendment. Singly grown seedlings were able to develop spontaneous haustoria at similar levels as those grown with another conspecific seedling. In view of the fast and abundant formation of spontaneous haustoria, P. kansuensis may be developed as an excellent experimental system in future investigations for unraveling endogenous regulation of haustorium initiation and development in root hemiparasitic plants.

N-P Fertilization Inhibits Growth of Root Hemiparasite Pedicularis kansuensis in Natural Grassland.

Fertilization has been shown to affect interactions between root hemiparasitic plants and their host plants, alleviating damage to the hosts by parasitism. However, as a majority of studies were conducted in pot cultivation, the influence of fertilizer application on root hemiparasites and the surrounding plant community in field conditions as well as relevant mechanisms remain unclear. We manipulated soil nutrient resources in a semi-arid subalpine grassland in the Tianshan Mountains, northwestern China, to explore the links between fertilization and plant community composition, productivity, survival, and growth of a weedy root hemiparasite (Pedicularis kansuensis). Nitrogen (at a low rate, LN, 30 kg N ha-1 year-1 as urea; or at a high rate, HN, 90 kg N ha-1 year-1 as urea) and phosphorus [100 kg ha-1 year-1 as Ca(H2PO4)2⋅H2O] were added during two growing seasons. Patterns of foliar nutrient balances were described with isometric log ratios for the different plant functional groups receiving these fertilization regimes. Fertilization with LN, HN, and P reduced above-ground biomass of P. kansuensis, with above-ground biomass in the fertilization treatments, respectively, 12, 1, and 39% of the value found in the unfertilized control. Up to three times more above-ground biomass was produced in graminoids receiving fertilizers, whereas forb above-ground biomass was virtually unchanged by the fertilization regimes and forb species richness was reduced by 52% in the HN treatment. Fertilization altered foliar nutrient balances, and distinct patterns emerged for each plant functional group. Foliar [C | P,N] balance in the plant community was negatively correlated with above-ground biomass (P = 0.03). The inhibited competitiveness of P. kansuensis, which showed a much higher [C | P,N] balance, could be attributed to reduced C assimilation rather than mineral nutrient acquisition, as shown by significant increase in foliar N and P concentrations but little increase in C concentration following fertilization.

Long-Distance Dispersal after the Last Glacial Maximum (LGM) Led to the Disjunctive Distribution of Pedicularis kansuensis (Orobanchaceae) between the Qinghai-Tibetan Plateau and Tianshan Region.

Quaternary climate fluctuations have profoundly affected the current distribution patterns and genetic structures of many plant and animal species in the Qinghai-Tibetan Plateau (QTP) and adjacent mountain ranges, e.g. Tianshan (TSR), Altay, etc. In this greater area disjunct distributions are prominent but have nevertheless received little attention with respect to the historical processes involved. Here, we focus on Pedicularis kansuensis to test whether the current QTP and TSR disjunction is the result of a recent Holocene range expansion involving dispersal across arid land bridge(s) or a Pleistocene range fragmentation involving persistence in refugia. Two chloroplast DNA spacers were sequenced for 319 individuals from 34 populations covering the entire distribution range of this species in China. We found a total of 17 haplotypes of which all occurred in the QTP, and only five in the TSR. Overall genetic diversity was high (HT = 0.882, HS = 0.559) and higher in the QTP than in the TSR. Genetic differentiation among regions and populations was relatively low (GST = 0.366) and little evidence for a phylogeographic pattern emerged. The divergence times for the four main lineages could be dated to the early Pleistocene. Surprisingly, the two ubiquitous haplotypes diverged just before or around the Last Glacial Maximum (LGM) and were found in different phylogenetic lineages. The Species Distribution Model suggested a disappearance of P. kansuensis from the TSR during the LGM in contrast to a relatively constant potential distribution in the QTP. We conclude that P. kansuensis colonized the TSR after the LGM. The improbable long-distance dispersal by wind or water across arid land seed flow may well have had birds or men as vector.

Host shoot clipping depresses the growth of weedy hemiparasitic Pedicularis kansuensis.

Root hemiparasitic plants show optimal growth when attached to a suitable host by abstracting water and nutrients. Despite the fact that damage to host plants in the wild occurs frequently in various forms (e.g. grazing), effects of host damage on growth and physiological performance of root hemiparasites remain unclear. In this study, host shoot clipping was conducted to determine the influence of host damage on photosynthetic and growth performance of a weedy root hemiparasite, Pedicularis kansuensis, and its interaction with a host, Elymus nutans. Photosynthetic capacity, tissue mineral nutrient content and plant biomass of P. kansuensis were significantly improved when attached to a host plant. Host clipping had no effect on quantum efficiency (ΦPSII), but significantly reduced the growth rate and biomass of P. kansuensis. In contrast, clipping significantly improved photosynthetic capacity and accumulation of potassium in E. nutans. No significant decrease in biomass was observed in clipped host plants. By changing nutrient absorption and allocation, clipping affected the interaction between P. kansuensis and its host. Our results showed that host clipping significantly suppressed the growth of weedy P. kansuensis, but did not affect biomass accumulation in E. nutans. We propose that grazing (a dominant way of causing host damage in the field) may have a potential in the control against the weedy hemiparasite.

Arbuscular mycorrhizal fungi: potential biocontrol agents against the damaging root hemiparasite Pedicularis kansuensis?

Spatial expansion of root hemiparasitic Pedicularis kansuensis in Bayanbulak Grassland of Xinjiang Uygur Autonomous Region (China) has caused great loss of herbage yield and has threatened the local livestock industry. Current management practices using manual eradication and chemical control have been proved problematic. Arbuscular mycorrhizal (AM) fungi have been suggested to be potential biocontrol agents against a number of plant pests, but experimental evidence is lacking against weedy P. kansuensis. In this study, we tested the hypothesis that inoculation with AM fungi will cause growth depression in P. kansuensis and reduce its damage to host plants. Based on the confirmation of AM status and host community of the hemiparasite in the field, a pot cultivation experiment was conducted to test the influence of an AM fungus (Glomus mosseae) on growth of P. kansuensis and the parasitized host (Elymus nutans). AM colonization was observed in roots of P. kansuensis, but the levels were much lower than those of its adjacent host species. A negative correlation between AM levels and the numbers of haustoria was detected for the field samples of the hemiparasite. Strong suppression of haustorium formation, a significant reduction in plant dry weight (DW), as well as marked reduction in the survival rate of P. kansuensis after inoculation with AM fungi was observed. In contrast, inoculation with G. mosseae increased root DW and whole plant DW of parasitized host plants. Our findings demonstrated significantly repressive effects of AM fungi on growth performance of P. kansuensis with and without the presence of a host. The potential of AM fungi as biocontrol agents against the damaging hemiparasite was confirmed.

[Influence of embryo transfer depth on in vitro fertilization and embryo transfer outcomes].

OBJECTIVE: To investigate the influence of transfer distance from the fundus on clinical pregnancy rate and implantation rate in in vitro fertilization and embryo transfer. METHODS: A total of 98 patients (108 cycles) undergoing ultrasound-guided embryo transfer were divided into two groups according to the distance between the tip of catheter and the uterine fundus: group A: > or = 5 - < 10 mm, group B: > or = 10 - < or = 15 mm. RESULTS: Clinical pregnancy rate and implantation rate were significantly higher in group B compared with group A [44 % (23/52) vs 25% (14/56), 24% (28/115) vs 14% (17/121), P < 0.05]. The multiple pregnancy rate, ectopic rate and miscarriage rate were similar in the two groups (P > 0.05). CONCLUSION: The depth of the embryo replacement into the uterine cavity may influence pregnancy rate and implantation rate.

[Cryopreservation of mouse morula and blastocysts by vitrification].

OBJECTIVE: To compare the survival and developmental potential of mouse morula, early blastocysts and blastocysts cryopreserved by vitrification. METHODS: One hundred and forty-two mouse morula, 135 early blastocysts and 148 blastocysts were cryopreserved by 6 mol/L ethylene glycol and 1 mol/L sucrose vitrification solutions. The survival rates and blastocysts hatching rates after thawing were observed. RESULTS: The survival rates of morula, early blastocysts and blastocysts groups were 88.0%, 73.3%, and 60.1% respectively. The blastocyst hatching rates were 73.9%, 61.5%, and 49.3% respectively. Both the survival rates and blastocyst hatching rates in morula group were higher than those in early blastocysts group (P < 0.05), and they were higher in early blastocysts group than in blastocysts group (P < 0.05). CONCLUSIONS: In these three embryo stages, the survival and developmental potential of mouse morula cryopreserved by vitrification are better than those of early blastocysts and blastocysts. Morula is likely the most feasible stage for embryo vitrification.

[Effect of luteinized granulosa cell conditioned medium on cortical granule of mouse oocytes matured in vitro].

OBJECTIVE: To study the effect of luteinized granulosa cell conditioned medium on cortical granule (CG) of the mouse oocytes matured in vitro. METHODS: Oocytes in germinal vesicle (GV) stage of Kunming mice were randomly divided into 2 groups according to different in vitro maturation (IVM) culture media. The study group medium contained 50% granulosa cell condition medium, follicle stimulating hormone 75 U/L and estrodial 1 nmol/L. The control group medium contained follicle stimulating hormone 75 U/L and estrodial 1 nmol/L. Oocytes were cultured for 16 or 18 hours. CG was examined by fluorescein isothiocyanate labeled Lens culinaris agglutinin under a confocal scanning laser microscope. RESULTS: After cultured for 16 hours, the nuclear maturation rates of control and study groups were 70.0% and 76.5%. After cultured for 18 hours, the maturation rates were 75.1% and 83.1%, respectively. There was no significant difference between the two groups. After cultured for 16 hours, there was no pronuclear formation in both groups. When culture was extended to 18 hours, fertilization occurred. After cultured for 16 hours, the rates of CGs forming a line under membrane were 10.0% and 50.0% in control and study groups respectively. When culture was extended to 18 hours, the rates rose to 57.1% and 91.6% accordingly. The rate of 18 h of each group was significantly higher than that of 16 h (both P < 0.001). The rate of study group of 18 h was significantly higher than that of control group (P < 0.05). CONCLUSION: Granulosa cell conditioned medium could improve the mouse oocytes maturation competence in vitro.