Bitkilerde polen gelişiminin sağlıklı ilerlemesinde anter çeper tabakalarının düzenli gelişimi önemli bir role sahiptir. Bu katmanlardan en dışta bulunan epidermis anter gelişimi sırasında iç dokuyu ...koruyucu görev üstlenirken altına konumlanan ve boyuna uzamalar gösteren endotesyum tabakasının hücreleri polenler anteri terk edeceği zaman maksimum gelişme göster. Bir veya iki sıralı geçici hücrelerden meydana gelen ara tabakanın altında bulunan tapetum hücrelerinin ise polen verimi ile yakından ilişkisi bilinmektedir. Mikrosporların beslenmesi, ekzin çeper oluşumu, mikrosporların tetrattan salınması, polen tanesinin pistil stigmasında tanınmasının sağlanması gibi süreçlerde önemli rolü olan tapetumun gelişim aşamalarında programlı hücre ölümüne uğradığını gösteren sitolojik çalışmalar bulunmaktadır. Çalışmamızın amaçlarından biri, Hibiscus syriacus L.’nin anter gelişiminin ve sitokimyasal içeriğinin incelenerek Malvaceae familyasının embriyolojik bulgularına katkı sağlamaktır. Anter gelişiminin farklı aşamalarındaki çeper tabakalarının sitokimyasal yöntemlerle analiz edilmesi amacıyla H. syriacus’a ait çiçek tomurcukları farklı gelişim evrelerine göre ayrılarak fikse edilip parafine gömülmüş, sonrasında ışık mikroskobisi için Hematoksilen, Coomassie parlak mavisi, Periyodik asit-Schiff ve Sudan siyahı B boyaları ile boyanmıştır. Bunun yanında anter çeper tabakalarında gerçekleşen programlı hücre ölümünün karakterizasyonu DAPI boyaması ile karakterize edilmiştir. Elde ettiğimiz verilere göre anter çeper tabakalarına ait hücrelerde genç mikrospor safhasında başlayan ve ileri mikrospor safhasında şiddetlenerek devam eden nukleus bozukluklarına bağlı hücre ölümleri gözlenmiştir. Olgun mikrospor safhasında ise tapetum ve ara tabakanın tamamen köreldiği belirlenmiştir. Ayrıca H. syriacus’a ait mikrosporların morfolojik ve sitokimyasal incelemelerine de çalışmamızda yer verilmiştir.
The word pteridophyta is derived from Greek words “pteron” means “feather” and “phytes” means “plants” (i.e. feather like plants). They are spore bearing, seedless vascular cryptogams characterized ...by the self-regulating heteromorphic alternation of generation. They grow luxuriously in different habitat during rainy season due to the presence of high humidity, moisture content in the atmosphere and enough shade due to less penetration of sunlight. They stands at second position in terms of species richness while, their diversity and distribution ranks next to the angiosperms in plant kingdom. It is estimated that, about 11,916 species representing 337 genera in 51 families showing cosmopolitan distribution in different biogeographic zones of the world (PPG-I 2016). A cosmopolitan distribution of pteridophytes in India comprises about 1,138 species and 114 subspecies belonging to the 125 genera, of 34 families (Fraser-Jenkins et al. 2017, 2018a, 2020; Fraser-Jenkins 2020). From which, 47 species of 20 genera belonging to 15 families of pteridophytes are endemic to the country (Fraser-Jenkins 2008a; Fraser-Jenkins et al. 2017, 2018a, 2020; Fraser-Jenkins 2020).The term gymnosperm is attaining from a Greek “gymnospermos” means “naked seeds” (i.e. seeds not encircled with cotyledons). Gymnosperm is the group of tracheophyta where, ovules are is not encircled in carpel, unlike angiosperms (Singh & Srivastava 2013). In contrast to other group of plant, living gymnosperms are very fewer in number; they comprise ca. 1,106 species under four major lineages viz., Ginkgo, Gnetophytes, Cycads and Conifers (Calonje et al. 2020; WCSP 2020). In India, extant gymnosperms diversity is estimated about 149 species and 8 varieties (indigenous/introduced) belonging to 46 under belonging to 12 families (Singh & Srivastava 2013; Sharma & Singh 2015; Akhtar et al. 2019).As compared to other groups of plant, angiosperms have received great attention for its diversity and distribution in the state. Similar studies on pteridophytes are not being reflected in botanical literature due to the lack of enumeration/excursion studies. Few species are known from state usually has information only from a few localities and no detailed studies are carried out on this group of plants in Gujarat state due to aforesaid reasons. In similar case for gymnosperm diversity and only Ephedra foliata L. is documented from few places of Saurashtra and Kachchh. However, I feel that there is an existence of more than one species of Ephedra from the Gujarat state. Therefore, in the present study aimed to explore the diversity and distribution of pteridophytes and gymnosperms occurring in different biogeographic zones and regions of Gujarat state and their molecular identification using DNA barcoding techniques is undertaken.
One of the major goals of evolutionary biology is to explain trait variation within and among species. Much of the tremendous diversity in floral traits across angiosperm lineages is thought to ...reflect a history of close ecological associations with animals. While pollinator mediated selection on morphological traits has received much attention, surprisingly few have included floral scent into ecological or evolutionary analyses. Fewer still have compared the relative importance of such traits in mediating both animal pollination and predation using linear, quadratic and correlational models. Finally, this dissertation serves to document the first analysis of floral scent in the genus Castilleja. The purpose of this dissertation was to study plant-animal interactions mediated by morphological traits and floral scent. Data collected from natural populations were used to address the following questions in the genus Castilleja: 1) Does interspecific variation in plant traits predict pollinator visitation?; 2) To what extent does intraspecific variation in plant traits mediate both mutualistic and antagonistic interactions?; and 3) What forms of selection result from multiple plant-animal interactions affecting floral scent and morphological traits?We demonstrated that variation in floral morphological and scent traits among five species of Castilleja differentiated species and pollination syndromes, but did not reliably predict pollinator visitation. Extremely low rates of pollinator visitation across Castilleja species reduced statistical power of analyses reliant on direct observational data. However, using direct observations of antagonist seed predator visitation and indirect measures of seed predator and pollinator activity we detected associations between plant traits and animal behavior within a large population of Castilleja sessiliflora. While pollinator and seed predator activity was correlated with both morphology and scent, their activities were predicted by distinct traits. Directional, stabilizing, disruptive, and correlational selection were detected; and traits that experienced selection were evident during the seed initiation stage, suggesting a potential role of pollinators. However, marked changes in the direction and magnitude of selection were evident following visitation by seed predators. Overall, these results demonstrate that both scent and morphological traits mediate plant-animal interactions, and that both mutualists and antagonists significantly contribute to selection on plant traits.
Burl is an unwanted out-growth or swelling on main stem and lower branches of mango tree seems like tumour. This disease is lesser known but widely spread throughout Indian and some other countries. ...Therefore, the study was done to carried out, disease incidence and several morphological characteristics viz., burl shape, colour, surface texture, position of burl formation from ground level on the stem, the total number of burls per plant, the height of the first burl from ground and presence of gummosis for the prevalence of burl disease in different germplasms. Nearly, 473 germplasm were screened among them 34 germplasm found susceptible with 7.18 % disease incidence. In Gujarat state, 167 germplasm were screened and 20 germplasm found infected with 12% disease incidence. Maximum disease incidence (100%) was recorded in approx. 14 germplasm while minimum incidence was found in Desi, Khodi and kesar germplasm. The shape of burl was recorded globose to elongated, globose to semi-elongated and irregular in many germplasm. The burl colour was also recorded during the investigation and colour noted as brownish-black, greyish-black, brownish-grey to brownish-black and blackish-brown. The surface structure of mango trunk was also noted and it was found rough in majority while smooth surface in some germplasm. The size of the burl was larger in Langra (36.00 cm2), followed by Desi (32.00 cm2), whereas it was minimal in Mankurad (10.0 cm2) in Gujarat state. The fruit yield loss was also observed and the maximum fruit yield loss was found in Mahmood Vikarabad (21.56 %) and Langra (20.22 %) followed by Hybrid 10 (17.81 %), Sukul (14.30 %) Sindhu (15.40 %) and Seedling (12.30 %) whereas lowest fruit yield loss was recorded in Olour (2.30 %), Alphanso × Baneshan (0.83 %) and Alphanso × Sabja (0.47 %), respectively. Based on morphological (colony characters, gram staining and plate essay) and molecular characterization (phylogenetic analysis) the pathogen was identified as Agrobacterium tumefaciens. Pathogenicity test was also applied to confirm the pathogen and to prove Koch’s postulate. Wood anatomy of healthy (normal) stem and burl was also investigated and when compared with healthy and affected wood tissue, drastic alterations were not only observed in the composition of wood of healthy and burl affected trees but also showed alterations in the structure of the individual xylem elements. The secondary xylem elements viz. vessel elements and ray cells of this portion were sealed with tyloses. Biochemical changes in fruit and wood of burl infected and non-infected plants were also analysed. Fruits of the burl affected plants of Langra and Rajapuri varieties showed maximum content of TSS (18.8 °brix), total soluble sugar, reducing sugar, non-reducing sugar and ascorbic acid while the acidity was found minimum. Total eleven parameters such as total contents of moisture, ash, cellulose, fibre, lignin, total soluble sugar, reducing sugar, non-reducing sugar, total phenol, starch and ascorbic acid were examined and compared with normal and burl portions. Similarly, there is an increase in moisture content, cellulose, lignin and other parameters in the burl wood. In conclusion, burl disease is an important disease of mango because it causes great economic loss in mango production in India and throughout the world. In India, several varieties like Arka Aruna, Mahmood Vikarabad, Langra etc., are highly susceptible to it while other varieties like Desi, Khodi and Kesar are relatively resistant Amrapali, Mallika, Totapuri and Vanraj are found free from the burl disease. External injury during agricultural practices may be the major source of pathogen entry in the tree. Another possible reason is the source of stock used in the grafting source may be responsible for the incidence of the disease. This statement may be supported by the fact that trees growing naturally in forest areas and open area wild germplasms showed no disease incidence. For the management of disease, primary management methods can be established or applied to manage the disease including, proper tree management, avoiding wounding or pruning of trees from orchard may reduce impacts of the disease. Types of equipment used in the pruning of the trees should be disinfected frequently when in use because infected equipment can spread pathogen during pruning operations. The complete eradication of burl by chemical treatment is not known but farmers should remove burl from the tree trunk and apply copper oxychloride or Bordeaux paste mixed with compatible insecticide (methyl-demeton or monocrotophos) is a good way to control this disease. The fungicidal paste Chaubattia paste can also be applied to the wounds during the pruning operations in the first fortnight of October.
For centuries, poets have been ensnared - as one of their number, Andrew Marvell put it - by the beauty of flowers. Then, from the middle of the eighteenth century onward, that enjoyment was enriched ...by a surge of popular interest in botany. Besides exploring the relationship between poetic and scientific responses to the green world within the context of humanity's changing concepts of its own place in the ecosphere, Molly Mahood considers the part that flowering plants played in the daily lives and therefore in the literary work of a number of writers who could all be called poet-botanists: Erasmus Darwin, George Crabbe, John Clare, John Ruskin and D. H. Lawrence. A concluding chapter looks closely at the meanings, old or new, that plants retained or obtained in the violent twentieth century.
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