Effects of Plant Age, Topography and Processing System On the Biochemical Traits and Quality of Tea

Laboratory experiment was conducted to study the biochemical and quality parameters of tea i.e. Polyphenol, Theaflavin (TF), Thearubigin (TR), Caffeine, Lipid, Total ash, Chlorophyll, Moisture content etc. under different variables designed for age, topography, and processing system imposed on an established tea orchard. Results revealed that plant age and topography do not have any significant effect on most of the studied parameters. In case of plant age, tannin is found to be significantly higher in mature tea plant (39.35 ppm) whereas young plant showed significantly lower total sugar content (28.98 ppm). In case of land elevation, significantly higher tannin (37.41 ppm) and lower carotenoid content (0.74 mg/g) were evident in plants from kunchi topography where flat topography showed significantly higher total sugar (26.62 ppm) in leaves. The handmade tea flavoured with significantly higher amount of polyphenol (58.57 ppm) and caffein (43.30 ppm) but industry made tea showed significantly higher amount of tannin (37.65 ppm), total sugar (15.25 ppm) and TF:TR (1:10). Bangladesh J. Bot. 50(3): 633-639, 2021 (September)

Relationships Among the Feeding Behaviors of a Mirid Bug on Cotton Leaves of Different Ages and Plant Biochemical Substances

Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) tends to feed on young plant tissues. To explore the relationship between stylet probing behaviors of adult A. lucorum and conditions of cotton leaves, we conducted an experiment using electropenetrography (EPG). Behaviors were recorded on four cotton varieties, in relation to thickness and biochemical traits of differently-aged leaves. Cotton leaf age had a significant effect on the probing behavior of A. lucorum but cotton variety did not. One-day-old leaves of A. lucorum received the highest mean number of stylet probes (penetrations) per insect, and longest mean durations per insect of combined stylet probing or its components, cell rupture and ingestion behaviors. All of the leaf traits (thickness and biochemical substances) were similar among these four cotton varieties. Leaf thickness had a significantly negative effect on the same four variables above. Gossypol and tannin also had a negative impact on combined probing duration. Redundancy analysis showed that the four EPG variables were closely related to nutrient substances (amino acids, sugar, and water) while they had the opposite relationship with plant defense substances (gossypol and tannin). On cotton in the seedling stages, A. lucorum fed more readily on the youngest, thinnest leaves in our no-choice EPG experiments. Nutrients and chemical resistance substances determined the probing duration of A. lucorum. Our findings can contribute to better understanding of patterns of feeding and host consumption by A. lucorum, ultimately improving cotton resistance to A. lucorum.

Response of three tossa jute (Corchorus olitorius L.) cultivars produced in Benin to salinity stress at germination and young plant stages

The response of three tossa jute cultivars Ordinaire, 5-Doigts and Acc : Sud 2 to salt stress was evaluated at germination and young plant stages. Five NaCl concentrations: 0; 30; 60; 90 and 120 mM NaCl were used. Seeds were submitted to NaCl in petri dishes and germination was checked every day during thirty days in a completely randomized design with four replicates. Four-week old plants were submitted in pots to the same five NaCl concentrations by irrigation every two days for two weeks in screen house. NaCl reduced seed germination rate in all cultivars from day 2 to day 30 and the germination index. At the end of the 30 days, salt stress reduced the final germination percentages with a significant difference among cultivars: cultivar 5-doigts was the least affected than the two other cultivars. Salt effect caused a reduction of young plant growth whatever the growth parameter considered with a significant difference among cultivars. The growth of cultivar Acc:Sud 2 was more affected by salt stress with the lowest salt tolerance index whereas that of cultivar Ordinaire was the least affected with the highest salt tolerance index. Thus, cultivar 5-Doigts appeared as the most resistant to salt stress at germination stage among the three cultivars; whereas cultivar Ordinaire followed by 5-Doigts was the most salt resistant at young plant stage.

Stimulasi Pertumbuhan Kina Belum Menghasilkan (TBM) dengan Aplikasi Konsentrasi BAP Setelah Fase Pembentukan Batang

Cinchona is plantation commodity that useful as medicine material. Productivity of cinchona is influenced by growth phase on young plant. For increasing the productivy of cinchona should be applied stem shaping and combine with growth regulator. This research aims to get the precise concentration of growth regulator for young cinchona after stem shaping. The experiment was observed at Ciparanje field station of Agriculture Faculty, Padjadjaran University, Jatinangor. It used randomized block design with 6 treatments and 4 replications (3 plants for each plot). The treatments were 6 levels of BAP (0 ppm, 30ppm, 60ppm, 90 ppm, 120ppm and 150 ppm). The result showed that BAP level had significant effect for growing of young cinchona. 30 ppm of BAP influenced branch growth meanwhile 90 ppm and 150 ppm had significant effect on leaves number and stem diameter was influenced by all of BAP concentrations.

Response of seven tomato (Lycopersicon esculentum Mill.) cultivars produced in Benin to salinity stress at young plant stage

In this study, we evaluated the salt resistance level of seven tomato cultivars Akikon, Tounvi, Thorgal, F1 Mongal, Padma, Petomech and TLCV15 at young plant stage. The experiment was laid out as a Randomized Complete Design (RCD) with four replications in a greenhouse. Three-week old plants from the seven cultivars were submitted in pots containing a mixture of potting soil and sand to five NaCl concentrations: 0; 30; 60; 90 and 120 mM NaCl corresponding respectively to an electric conductivity of 0.221; 3.827; 6.47; 10.56 and 14.02 dS.m-1 by irrigation every two days. Plant growth parameters were evaluated after two weeks. Salt effect caused a reduction of young plant growth whatever the growth parameter considered with a significant difference among cultivars. Growth of cultivars Padma, Akikon and Petomech was more affected by salt stress with two or three growth parameters significantly reduced at 30 mM NaCl whereas no growth parameter was significantly affected at less than 60 mM NaCl for cultivars Thorgal and Tounvi. Thus, cultivars Akikon, Petomech and Padma appeared as the most sensitive to salt stress. In contrast, cultivars Tounvi and Thorgal appeared as the most salt-resistant. Cultivars F1 Mongal and TLCV15 had intermediary behavior.

The Study of Antioxidant Capacity in Extracts from Vegetal Sources with Hypoglycaemic Action

In the dental office, diabetes mellitus is a chronic affection that many patients suffer. Apart from the treatment of all diabetic patients, they use homeopathic medicines. We consider the importance of knowing these extracted hypoglycemic plants and their way of acting by the dentist.In this study we investigated some extracts obtained from vegetal sources used by hypoglycaemic action: Juglans regia L. -nut, Morus nigra L. -black mulberry, Olea europaea L. -olive. We followed the level of antioxidant compounds and the antioxidant capacity in the alcoholic extracts. Our results indicate higher antioxidant efficiency in the extracts from young plant parts, with meristematic tissues, and also a modified phytochemical profile, compared to the extract from mature plant parts.

Ex situ initial seedling development of Hymenaea courbaril L. (Fabaceae): a crucial phase to preserve the species

ABSTRACT Hymenaea courbaril L. is an important Neotropical species, with low population density, restricted to fragments of semideciduous forests, with low mortality and low recruitment. Thus, some questions guided the goals of this paper including the capacity of stored seeds to form normal seedlings. Seeds collected from ten mother plants in the Brazilian Cerrado region and stored during three years were mechanically scarified, sown and analyzed during 43 days. Intraspecific variability was observed for water content, seed biometry, and emergence process. The seedling emergence varied from 19 to 92%. Nine phases of development were observed. About 91% of the seedlings reached their complete autotrophy and this represents the success of the sample; the rest of the seedlings presented atypical morphology. This means that it is possible to store the seeds with the purpose of obtaining seedlings for ex situ cultivation. The great consumption of the cotyledon reserves occurred in the period that marks the alignment of cotyledons with hypocotyls (phases 1 to 4). For this species, if the seeds are scarified, the first 40 days after sowing are essential for the seedling establishment. After this time, the cotyledons fall signing a good point of reference for restoration projects because it indicates that the young plant is autonomous.

TOR and RPS6 transmit light signals to enhance protein translation in deetiolating Arabidopsis seedlings

Deetiolation is an essential developmental process transforming young plant seedlings into the vegetative phase with photosynthetic activities. Light signals initiate this important developmental process by triggering massive reprogramming of the transcriptome and translatome. Compared with the wealth of knowledge of transcriptional regulation, the molecular mechanism underlying this light-triggered translational enhancement remains unclear. Here we show that light-enhanced translation is orchestrated by a light perception and signaling pathway composed of photoreceptors, CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1), the phytohormone auxin, target of rapamycin (TOR), and ribosomal protein S6 (RPS6). In deetiolating Arabidopsis seedlings, photoreceptors, including phytochrome A and cryptochromes, perceive far-red and blue light to inactivate the negative regulator COP1, which leads to activation of the auxin pathway for TOR-dependent phosphorylation of RPS6. Arabidopsis mutants defective in TOR, RPS6A, or RPS6B exhibited delayed cotyledon opening, a characteristic of the deetiolating process to ensure timely vegetative development of a young seedling. This study provides a mechanistic view of light-triggered translational enhancement in deetiolating Arabidopsis.