The flora of Erath County, Texas, U.S.A.

Knowledge of county floras in Texas is crucial for determining species composition, management, preservation, and restoration across the state. Like most Texas counties, floristic data for Erath County, Texas, is poorly known. The objectives of this investigation were to compile a flora for Erath County, determine the intro-duced, endemic, threatened, and endangered species, as well as make comparisons to the county’s original flora and that of the North Central Texas region. Field work was conducted from September 2003 to December 2009 at 35 sites in Erath County. In addition herbaria were searched to locate specimens from Erath County. A total of 870 species (888 taxa) were identified in 103 families. One hundred forty-four taxa were introduced while 744 taxa were native. Eighteen of the species are Texas endemics. There were two rare plants, Dalea reverchonii and Penstemon guadalupensis, but no threatened or endangered plants were found during the inves-tigation. Four state-listed noxious species were collected during the investigation—Arundo donax (giant reed), Convolvulus arvensis (field bindweed), Tamarix chinensis, and T. gallica (salt-cedars).

Metabolic Profile and Mycoherbicidal Activity of Three Alternaria alternata Isolates for the Control of Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium

Alternaria alternata isolates C1, S1, and X3 were isolated respectively from the weeds Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium in Algiers during 2016 and identified by morphological and molecular analyses. The aim of this investigation was to chemically characterize the exometabolome of these fungi and to evaluate the myco-herbicidal potential of their culture filtrates, crude extracts, or fractions towards target weeds. Results revealed a great heterogeneity in the biochemical profiles of the exometabolome with the remarkable presence of two compounds: tenuazonic acid (TeA) and triprenyl phenol-7 (SMTP-7). To the best of our knowledge, SMTP-7—found in all the isolates—as well as 12-methoxycitromycin detected in the culture filtrate of isolate C1, have never been reported to be produced by A. alternata. Some fractions of isolates C1 and S1 showed symptoms (necrosis and chlorosis) on the detached leaves of C. arvensis and S. oleraceus, respectively with up to 100% phytotoxic effect at low concentration. In conclusion, biochemical characterization revealed great difference of C1, S1, and X3 exometabolomethat is likely to explain the difference in their phytotoxic activity. Some fractions (d1, e1, h1, i1, a2, and f2) of isolates C1 and S1 of A. alternata caused severe necrosis and chlorosis on the injured detached leaves of C. arvensis and S. oleraceus, respectively.

Plant-based nanoparticles prepared from protein containing tribenuron-methyl: fabrication, characterization, and application

Background Tribenuron-methyl is a registered herbicide for broad-leaf weed control in wheat, however, low solubility in water and reacting with hard water's ions could substantially decrease its efficacy. The present work aimed to enhance the dispersing and bioactivity of this herbicide by developing nanoparticles using zein as a promising nano-delivery system and to assess the effects of nanoparticles on the efficacy of tribenuron-methyl in the suppression of Convolvulus arvensis as a problematic weed in wheat fields. Results Based on SEM analyses nanoparticles sizes were 80–120 nm. DLS results showed an average size of 170 nm for tribenuron-methyl zein-based nanoparticles (TMZNP-5). The entrapment efficiency (EE%) of tribenuron-methyl inside the zein nanoparticles was ca. 81% ± 3. Five-week after application of tribenuron-methyl nanoparticles on C. arvensis, it was able to reduce the dry weight (53%), acetolactate synthase (ALS) enzyme activity (82%), and plant height (77%) of C. arvensis as compared with untreated plants. Additionally, tribenuron-methyl used in nanoparticles at the half rate of the recommended dose had the same efficacy as commercial tribenuron-methyl. Conclusion Based on these results, zein nanoparticles can be potentially utilized as nanocarriers for enhancing the solubility of tribenuron-methyl to further enhance its bioavailability and performance on sensitive weeds. Graphic abstract

The features of xylem tracheary elements in some herbaceous members of the family Convolvulaceae Horan.

Numerous narrow xylem tracheary elements (tracheids and vessels) are present in liana stems, along with a few wide vessels that perform the main water-conducting function. This trait, known as “vessel dimorphism”, has been identified in studies on water-conducting tissue in autotrophic plants, including a large number of perennial climbing plants and a number of annual vines. Information is lacking on the presence of vessel dimorphism in parasitic plants of the lianescent habit. In this study, we performed a structural analysis of stems in the autotrophic herbaceous vines of Convolvulus arvensis L. and Calystegia sepium (L.) R. Br., as well as in the parasitic vines of Cuscuta monogyna Vahl, Cuscuta planiflora Ten., Cuscuta approximata Bab., and Cuscuta campestris Yunck., of the family of Convolvulaceae Horan. The xylem of C. arvensis and C. sepium contains a few wide conductive elements and many narrow ones. This feature is typical of autotrophic climbing plants. Only narrow tracheary elements are present in the xylem of the parasitic vines of the genus of Cuscuta L. (dodders). The total number of the tracheary elements is an order of magnitude less in the dodders than it is in the autotrophic vines. It is possible that the autotrophic ancestor of dodders lost the characteristic feature of the xylem of climbing plants, known as vessel dimorphism, during its transition to the parasitic lifestyle.

SOIL WEED SEED BANK STATUS IN THE AGROECOLOGICAL CONDITIONS OF CHITRAL, PAKISTAN

A greenhouse experiment was carried out at the Agricultural Research Station (ARS), Shen Lasht, Chitral during 2016-17. There were five different locations in district Chitral from where the soil samples were collected which included Drosh, Shen Lasht, Garam Chashma, Ayun and BoonyLasht. A total of 300 samples were collected from all locations with 60 samples from each location. The 300 soil samples collected were placed in trays of medium sizes i.e. 27 cm x 21 cm x 4 cm = 2268 cm3. The trays were arranged in three repetitions having 100 samples in each repetition. Each repetition of 100 samples contained samples from 5 locations, in each location 4 sites (east, west, north and south each at 100 m distance from each other) and at each site samples were collected from 5 different depths, making a total of 100 samples in one repetition i.e. 5 x 4 x 5 = 100 and with repetitions making a total of 300 samples in one district. The results indicated that in the soil samples of district Chitral a total of 31 noxious weeds were recorded. Out of the 31 different weeds, 23 were broad leaves, eight were grasses and one was sedge. In another angle, 24 weeds were annuals while the rest were perennials out of the 31 weeds identified. A total of 17 different plant families were represented by the weeds recorded in the soil samples of Chitral region. Among the different locations of Chitral, the highest weed seed bank was recorded in the soil samples of ARS Shen Lasht area. Weed seed banks have always been higher in areas with mild winters, where the Shen lasht area is having milder winters as compared to the other areas in Chitral. The lowest seed bank was recorded in the soil samples of Garam Chashma, which was however statistically at par with the rest of the locations studied in Chitral. As far as the seed banks in the depths are concerned, largest weed seed bank was observed in the depth of 6 to 12 cm. The smallest seed bank was at the depth of 30 cm followed by the depth of 24 and 18 cm. Therefore, it is evident that the major weed seed bank lies in the upper 6-12 cm depth of the soil. In case of the interaction, the largest weed seed bank was recorded at ARS Sheen lasht at the depth of upper 6 cm of the soil profile whereas the weed seed bank was very low below the 12cm depth of soil upto 30 cm in the Garam Chashma area of Chitral. Out of the total 31 weeds recorded in soil samples of Chitral, the top 10 weeds in terms of the relative weed densities, relative weed frequencies and importance value indices were Convolvulus arvensis, Rumex crispus, Poa annua, Galium aparine, Avenafatua, Trianthemaportulacastrum, Silybum marianum, Sorghumhalepense, Euphorbia helioscopia, and Loliumtenulentumspecies. The IVI values for these weeds were 14.01, 13.96, 13.07, 11.83, 11.57, 11.12, 10.35, 10.09, 10.02, and 9.99, respectively. Moreover, these IVIs indicate that out of the topmost 10 problematic weeds eight weeds are broad leaved and two are grassy weeds.

تأثير بعض المستخلصات النباتية والرواشح الفطرية على الفترة الزمنية لأنبات وقتل بذور المديد L. Convolvulus arvensis

اختلف التردد العددي لانبات وقتل بذور المديد L. Convolvulus arvensis في التركيزين 50 و 100 ملغم/مل للمستخلصات النباتية حيث شرع اول انبات للمعاملة السيطرة في اليوم الرابع بينما سجل اول انبات للمعاملة نبات الحندقوق Melilotus indicus في اليوم السادس , بالنسبة للتركيز 50 ملغم/مل وقد سجل اول حالة قتل في اليوم الحادي عشر بالنسبة للنوع Euphorbia peplus في حين تفوق المستخلص النباتي الجرجير Eruca vesicaria على جميع المعاملات في عملية القتل في جميع ايام الدراسة اما عند التركيز 100 ملغم/مل فقد سجل اول انبات لبذور المديد في اليوم السابع في معاملة مستخلص ام الحليب Sonchus oleraceus بينما سجلت اول حالة قتل في اليوم الرابع عشر بالنسبة لمستخلص فربيون Euphorbia peplus و مستخلص الكلغان Silybum marianum , كما اختلف التردد العددي لتأثير الرواشح الفطرية في انبات بذور المديد في التركيز 50 ملغم/مل . سجل اول شروع للانبات في اليوم الخامس في معاملة الراشح Penicillium resticulosum بينما سجلت اول حالة قتل في اليوم العاشر للراشح A. alternate اما في التركيز 100 ملغم/مل فقد سجلت اول حالة انبات في اليوم السادس للراشح الفطري Penicillium resticulosum كما سجلت اول حالة قتل للبذور في اليوم الحادي عشر للراشح Alternaria alternata.

Weed communities with alien plant species on the south-east area of the Orenburg Region

The presence of agrocoenotic factors constantly acting on segmental (weed-field) communities leads to a high level of community invasion - a potential opportunity to accept new species. In many cases, it is through synanthropic communities that invasions of alien species occur in the Urals, which cause significant damage to both agriculture and the entire economy of the region as a whole. The aim of investigation is to survey and identify the coenotic diversity of communities involving alien species in the steppe zone of the southeastern part of the Orenburg Region. The paper provides data on weed communities with the participation of Acroptilon repens , the Sisymbrium volgense and Artemisia sieversiana . Communities were identified in spring wheat crops in the southeast of the Orenburg Region (Dombarovsky and Svetlinsky administrative districts). Communities develop on dark chestnut soils in arid conditions of the steppe zone. As a result of a synaxonomic analysis, communities were classified into three new variants of the association Lactucetum tataricae Rudakov in Mirkin et al. 1985 previously described in the Republic of Bashkortostan. Perennial weed species prevail in the agrobiological spectrum of the coenoflora nucleus of the studied segetal communities, the share of which is 70%. The most active of them are root-sprung perennials, which are found with high constancy and often dominate: Acroptilon repens , Fallopia convolvulus , Cirsium arvense , Convolvulus arvensis , Lactuca tatarica , Euphorbia virgata . Using the indirect ordination method (DCA), the features of ecological differentiation of communities are demonstrated. The studied phytocoenoses are associated with the driest habitats with poor soils.

PALYNOMORPHOLOGICAL STUDY OF WEEDY MELLIFEROUS (BEE VISITED) PLANTS USING LIGHT MICROSCOPIC TECHNIQUES FROM SOUTHERN KHYBER PAKHTUNKHWA, PAKISTAN

Pollen morphology of 10 different weedy bee foraged plants belong to 10 various families from Southern Khyber Pakhtunkhwa were collected, identified and studied using light microscopy (LM). The plants were Asphodelus tenuifolius, Euphorbia helioscopia, Parthenium hysterophorus, Rhazya stricta, Datura innoxia, Eruca sativa, Convolvulus arvensis, Anagallis arvensis, Galium aparine, and Anethum graveolens. Slides for Light microscopic studies were prepared with the help of acetic acid, glycerin jelly and anthers of flowers. Pollen grain recorded ranged from monocolpate to hexacolporate and from psilate to echinate which were important systematic significance. Pollen size, shape, P/E ratio, exine thickness, number of colpi, number of pores, equatorial diameter, polar diameter, colpus width, colpus length, spines number, length and width of spines were examined with the help of light microscopy and all these values were analyzed statistically using software SPSS. This research provide a data to the optimal utilization of bee foraged weed plants by honeybees and identification of bee flora for the beekeeping business and honey production. Results revealed that weedy melliferous flora of study area is very helpful for botanical origin, geographical origin of bee species and adulterations found in honey.