Fresh Weight Ratio Research Articles

THE IMPACT OF LIGHT PENETRATION INTO CANOPY AND SEASONALITY ON PHOTOSYNTHETIC INDICES IN APPLE TREE LEAVES

The aim of this study was to analyse the impact of light penetration into canopy and the effect of distances between technological tools and seasonality on photosynthetic behaviour. Apple tree cultivar ‘Auksis’ was grafted onto superdwarfing rootstock P22 and planted at different distances (from 0,25 m to 1 m in rows, while space between rows was 3 m). Photochemical reflectance and plant senescence reflectance indices were measured at two heights: 1.0 – 1.2 m above ground and 1.8 – 2.0 m above ground; specific leaf area, fresh and dry weight were evaluated from all the canopy. Strong positive correlations were determined between photochemical reflectance index and plant senescence reflectance index in higher and lower levels of the canopy. Strong negative correlations were determined between photochemical reflectance index and plant senescence reflectance index and between specific leaf area and dry and fresh mass ratio. Increasing density between apple trees from 1 m to 0.5 m led to increase in photochemical reflectance index and specific leaf area, but plant senescence reflectance index decreased. Meanwhile, seasonality had significant impact on specific leaf area formation and dry to fresh weight ratio. Dry and fresh weight ratio increased by 5% in autumn compared to summer. Our results indicated that with decreased light penetration into canopy photochemical reflectance index decreased, but plant senescence reflectance index increased. Moreover, in autumn, trees prepare for winter by storing more nutrients and leaves accumulate more dry mass.

Effect of various planting distances on growth and carrageenan yield of Kappaphycus alvarezii (doty) using seedlings produced from mass selection combined with tissue-cultured method

Kappaphycus alvarezii (Doty), a red seaweed, is the most widely cultivated commodity in Indonesia. However, there is a decline in the cultivation production in the last three years. One way to overcome this problem is by improving the quality of seedlings through a development of farming. Efforts made from these are to develop farming techniques using different planting distances (PD) treatments. This study aimed to determine the effect of different PD on growth and carrageenan yield of K. alvarezii using seedlings produced from mass selection combined with tissue-cultured method. This research was conducted in Marobo coastal waters, Bone District, Muna Regency, SE Sulawesi, Indonesia. This study used a Completely Randomized Design (CRD) with three treatments based on different PD and five replications. The treatments were A: 10 cm PD, B: 15 cm PD, and C: 20 cm PD. The results show that the daily growth rate (DGR) of all treatments tended not to differ significantly. For 10 cm PD, the DGR tended to be higher and significantly different from the other two treatments, 15 cm and 20 cm. DGR averagely were 6.00±1.19%/day, 5.36±1.17%/day, and 5.27±1.62%/day for 10, 15, and 20 cm PD, respectively. The ratio of fresh weight (FW) and dry weight (DW) showed no significant differences among treatments. Ratio of FW:DW treatments of 10 cm, 15 cm, and 20 cm were 8.34:1, 9.58:1, and 8.98:1, respectively. For carrageenan yield, the treatment of 20 cm PD showed highest yield and it was significantly different from other treatments. Seaweed diseases and epiphytes found during this study were ice-ice and epiphytes (Sargassum polychystum).

BIOCHAR AS A STRATEGY TO ENHANCE GROWTH AND YIELD OF WHEAT PLANT EXPOSED TO DROUGHT CONDITIONS

Drought has become major environmental constraint to the crops productivity and the sustainability of agriculture. Recently, using biochar (BC) as a soil conditioner has aroused much interest and proved to be an effective tool for improving soil properties and crops growth and yield. Therefore, a pot trial was conducted using wheat plant (Triticum aestivum L.) with three water regimes (60, 30 and 15% of water holding capacity(WHC)) and three rates of biochar (0, 2%, and 5%) to investigate the impact of biochar on growth and yield components. The results showed that WHC enhanced in the presence of BC leading to improving the availability of water to wheat plants grown in BC-treated soil. Plants grown in BC-amended soil had higher growth and plant biomass, net assimilation rates than those in un-amended soil. Biochar addition positively affected wheat growth parameters including increases in leaf area, number of leaves per plant, tillers number per plant, height of plant as well as shoot to root fresh weight ratio. Particularly interesting is the improvements in yield attributes. These results led us to conclude that the application of black carbon would enhance the growth and yield of crops under insufficient water supply. On other hand, biochar can be considered an effective tool for sustainable agriculture and hence mitigating the injurious effects of drought conditions on plants.

Assessment of drought tolerant cotton genotypes based on seedling & physiological attributes at different moisture levels

Abstract The potential of any crop variety is subjected to various environmental conditions and a large fraction of the potential yield cannot be attained. For this study, fifty cotton genotypes of different origin were collected from gene pool of Central Cotton Research Institute, Multan and screened in the glass house. These genotypes were also evaluated under the field condition to obtain parents that possess better tolerance against drought. Initial screening of these genotypes was conducted in the glass house under three moisture levels 100, 70 and 40% at field water capacity. Data were recorded for root length, fresh root weight, dry root weight, root shoot length ratio, shoot length; fresh shoot weight, dry shoot weight, fresh root shoot weight ratio and dry root shoot weight ratio in glass house. Five drought tolerant genotypes (BH-176, MPS-11, DPL-45, Tree cotton and Cyto-62) and three susceptible genotypes (GS-444, Cooker-315, MS-64) were identified. Highly significant differences found among genotypes for all seedling characters. Further evaluation was done in field on the basis of various physiological parameters i.e. relative water content, excised leaf water loss, cell injury, leaf water potential, osmotic potential, net photosynthesis rate, transpiration rate and stomatal conductance under normal and water stress conditions. Same genotypes were confirmed under field studies. Highly significant genotypic variation existed among genotypes for all the physiological traits. The predicting genotypes may be selected and exploited to improve drought tolerance for the cotton crop. Keywords: Cotton; Drought; Physiological traits; Pakistan; Seedling traits; Tolerance http://dx.doi.org/10.19045/bspab.2018.700167

Assessment of Integrated Weed Management Approaches on Asphodelus tenuifolius in Chickpea

ABSTRACT: Chickpea is the third most important crop of rainfed areas of Pakistan, and it is severely affected by noxious weed Asphodelus tenuifolius. Therefore, a field trial was conducted to evaluate the effect of different allelopathic weed extracts, herbicides and mulches in controlling A. tenuifolius and other associated weeds in chickpea at “District Karak” Khyber Pakhtunkhwa-Pakistan. The experiment was carried out in a Randomized Complete Block Design (RCBD) and replicated thrice using a chickpea cultivar (Chattan) which was grown for the experimental trial. There were 9 treatments along with control for comparison. The treatments Stomp 330 EC (Pre-emergence) at 2.5 L ha-1, Fenoxaprop-p-ethyl, Bromoxanil+MCPA (Tank mix), Starane-M, mulching (Eucalyptus leaves), mulching (Wheat straw mulch), allelopathic weed extract (A. tenuifolius) + Stomp, allelopathic weed extract (Cyperus rotundus), allelopathic weed extract (Sorghum halepense) and control treatment were used in this trial. Data were recorded on A. tenuifolius density m-2 before and after application of weed management practices (m-2), A.tenuifolius fresh weight (m-2), seed yield (kg.ha-1), biological yield (kg ha-1) and cost-benefit ratio. Weed density before weed management was found to be non-significant. The data showed that minimum A. tenuifolius density after weed management and fresh weight (m-2) were found for Stomp 330 EC (6.33 m-2 and 1.98 kg m-2), which is statistically similar to Fenoxaprop-p-ethyl 6.9 EC (10.33 m-2 and 3.03 kg m-2) while maximum A. tenuifolius density and fresh weight (m-2) were recorded for control plots (74.33 m-2 and 287.46 kg m-2). Maximum seed yield (1,781.7 kg ha-1), biological yield (3,823 kg ha-1) and cost-benefit ratio (3.47) were recorded for plots treated with Stomp 330 EC, while the lowest seed yield (851.7 kg ha-1), biological yield (3,126.3 kg ha-1) and cost-benefit ratio (1.53) were observed for the control plot. Among the nutritive parameters in chickpea, maximum crude protein (17.40%), crude fat content (4.90%) and oil content (5.98%) were recorded for plots treated with Stomp 330 EC, while minimum crude protein (16.18%), crude fat content (4.12%) and oil content (5.01%) were found in the control plots. Thus, it is recommended that herbicides Stomp 330 EC and Fenoxaprop-p-ethyl should be used at pre-emergence at their recommended doses for control of A.tenuifolius and other associated weeds in chickpea crops.

Produksi selada (Lactuca sativa l.) dengan penyinaran lampu led merah dan biru di malam hari pada teknologi hidroponik sistem terapung termodifikasi

This research has an aim to observe the production of lettuce (Lactuca sativa L.) on hydroponic technology of floating system with red and blue LED (Light Emitting Diode) at night. This research was conducted inside the Screenhouse in which located on the top of Griya Kads House building, Bulusan Village, Tembalang Sub-district from May to June 2017. The research was conducted by 3x3 factorial experiments in Nested Design with 3 replications. The first factor was 0, 1.5 and 3 hours irradiation of red and blue LED lights at night. The second factor was 3, 5 and 7 ml/liter of AB mix nutrient concentration which was nested in the first factor. The data collected were fresh weight, dry weight and root canopy ratio. The results of the study showed that the treatment of AB mix nutrient concentration had no significant effect on all parameters. The production of lettuce with level of 5 ml concentration of AB mix was quite good, yet 3 ml and 7 ml levels didn’t improve lettuce production. The duration of red and blue LED irradiation only resulted in an increase in the production of canopy fresh weight. This research can be concluded that 3 hours was sufficient to give the good results to improve the results of lettuce plants production. Keywords : Lettuce Production, AB Mix Nutrition, Red and Blue LED.

Plant growth of Hedera helix and Chamaedorea elegans planted in pots in the hospital room

The purpose of this study was to investigate the changes of the growth of plants in the hospital ward depending on the types of media. After Hedera helix and Chamaedorea elegans which are the most commonly used for horticultural activities were cultured in three media such as horticultural bed soil, culture soil and tap water for 63 days, the growth status was examined. The results of the study are as follows. First, there was no significant difference in the plant height, leaf number and chlorophyll content of H. helix among three media. However, there was a significant difference in chlorophyll content of C. elegans as follows: Horticultural bed soil (SPAD=-0.2), culture soil (SPAD=-7.9) and tap water (SPAD=-14.7). There was no difference in the plant height among three media. Second, the changes of growth status between soil (horticultural bed soil and culture soil) and water (tap water) were compared. As a result, there was a significant difference in the height of H. helix (P=0.24). There was a significant difference in the chlorophyll concentration of C. elegans (P=0.24). Third, fresh weight and dry weight of plants growing in each medium were compared. The T/R ratio of fresh weight (9.51%) and dry weight (7.00%) of H. helix growing in horticultural soil was the highest. The T/R ratio of fresh weight (9.15%) and dry weight (9.00%) of C. elegans growing in tap water was the highest. According to the results of the investigation on the growth status of plants, there was no significant difference in the growth of H. helix depending on the media. However, it would be good for C. elegans to grow in soil rather than in tap water.

Management Practice of Cinnamomum tamala in Eladi VDC of Syangja, Nepal

Cinnamomum tamala is a moderate sized evergreen tree species which is used as spices in Indian subcontinent. In Nepal, it is found between 500- 2000 m above sea level. Its English name is Indian cassia lignea or Cinnamon. Leaves and bark of the species contain aromatic oil and are used as spices. The status and distribution of this species has less explored so this study has been carried out to assess the resource base and management practice at Eladi VDC of Syangja district. The researcher estimated the existing stand of Sinkauli, its annual increment, the annual allowable harvest, density, relative density, frequency, relative frequency and abundance along with its ethnobotanical uses. Community forests, National forest and private forest consisting of Sinkauli stands were inventoried based on the stratified random sampling. The scattered trees in the farmland and marginal land were enumerated and mesured. The measurement of DBH were stratified into different size groups at the interval of 5 cm DBH class and at 5 years interval of age classes. Altogether 98 trees were sampled from 0.14 ha area. For the measurement of fresh weight and air-dried weight of bark and foliage, thirty two sample trees representing the Sinkauli stand, were felled and measured.
 Data were analyzed by using different statistical tools like mean, diagrams, flowcharts, and pie chart. The density, relative density, frequency, relative frequency, abundance and growing stock are 13171, 55.34%, 100%, 11.7%, 13171, 700 trees/ha respectively. The air-dried weight to fresh weight ratio of bark of C. tamala is found to be 0.5210 and that of leaf is 0.5721. From this VDC, 345 trees of average age could be harvested with which 2944 kg bark and 2409 kg of leaves could be extracted annually. Based on the existing price at the local market, Rs 1177,60 from bark (RS 40/ Kg) and Rs 36130 from foliage (Rs 15/ Kg) could be earned annually.
 As people are less aware about the importance of C.tamala and the resource is dwindling from natural stand, the awareness program for its proper management, cooperation among different stakeholders, provision of economic market, and development of proper monitoring and evaluation program are recommended for the sustainable management of C.tamala stands.

Effect of detergent and sawdust addition on hydrocarbon reduction and growth of <i>Abelmoschus esculentus</i> L (Okra) in a petroleum-contaminated soil

A study to investigate the effect of sawdust and detergent on hydrocarbon reduction and the growth of okra (Abelmoschus esculentus L.) in petroleum polluted soil was carried out. The study was conducted at the Centre for Ecological Studies, University of Port Harcourt. Bonny light crude (300 ml) was used to pollute 10 kg soil. Detergent (20 g), sawdust (200 g) and sawdust: detergent (200 g: 20 g) were used as the amendment materials alongside a control (pollution but un-remediated) arranged in a completely randomized design of 12 replications. After 30 days post-amendment, 3 seeds of okra (var: V35-45 days) were grown in each treatment pot for 6 weeks. Soil Total Hydrocarbon Content (THC) and okra growth performance (shoot length, leaf number, root length, total fresh weight, dry weight, leaf area and leaf area ratio) were analyzed. Results showed significant (p=0.05) reductions in THC of 44.23%, 26.5%, 70.80% and 10.79%, in detergent (20 g), sawdust (200 g), sawdust (200 g) + detergent (20 g) and control, respectively. Improved growth performances of okra were observed in the amended soil as compared to the control. Okra growth performance was in the order of: 200 g sawdust + 20 g detergent combination > 200 g sawdust > 20 g detergent. This implies that these two materials are good bio-stimulation materials especially when used in combined form for THC reduction and growth of okra.Keywords: Abelmoschus esculentus L., contamination, crude oil, sawdust, total hydrocarbon content

Growth and Tissue Elemental Composition Response of Spinach (Spinacia oleracea) to Hydroponic and Aquaponic Water Quality Conditions

Spinach (Spinacia oleracea cv. Carmel) was grown in a conventional glass greenhouse under three different nutrient solution treatments. Lighting and temperature conditions were identical. Six growing systems were used to provide a duplicate trough system for each of these three treatments. Six trials were harvested from each system over a two month time period. Two treatments received hydroponic nutrient inputs, with one treatment at pH 7.0 (referred to as H7) and the other at pH 5.8 (H5), and the third treatment was aquaponic (A7), receiving all of its nutrients from a single fish tank with koi (Cyprinus carpio) except for chelated iron. System pH was regulated by adding K2CO3 to aquaponic systems and KOH to hydroponic systems. Comparisons made between treatments were total yield, leaf surface area, tissue elemental content, and dry weight to fresh weight ratio. Dry weight biomass yield values were not different in pairwise comparisons between treatments (A7 vs. H5: p = 0.59 fresh weight, p = 0.42 dry weight). Similarly, surface area results were not different between treatments. The important comparison was that A7 achieved the same growth as H5, the conventional pH with a complete inorganic nutrient solution, despite unbalanced and less than “ideal” nutrient concentrations in the A7 condition.

Growth of mango (Mangifera indica L.) rootstocks as influenced by pre-sowing treatments

An experiment was carried out at Navsari Agricultural University, Navsari during 2014 to evaluate the effect of pre-sowing treatments on survival percentage and growth of mango rootstocks. Mango stones were soaked in aqueous solutions of GA3 (100 and 200 ppm), Beejamruth (2 % and 3 %) and Thiourea (1 % and 2 %) for 12 and 24 hours. The trial was evaluated in Completely Randomized Design based on factorial concept and the treatments were replicated thrice. Imposition of treatments led to significant differences at 5 % level of significance for all parameters chosen in this study. Mango stones when treated with Thiourea at 1 % had the maximum shoot length (49.93 cm), root length (34.38 cm), shoot dry weight (21.08 g) and total dry weight (26.36 g). The highest number of lateral roots (10.90) and survival percentage (64.17) was observed in mango stones dipped in 100 ppm GA3. Between the two soaking duration, soaking mango stones for 24 hours recorded higher values for shoot length (45.03 cm), root length (32.79 cm), number of lateral roots (9.83), survival percentage (62.72), shoot root fresh weight ratio (4.30), shoot dry weight (21.33 g), total dry weight (26.28 g) and shoot root dry weight ratio (4.32). Thus, survival percentage and growth of mango rootstocks can be substantially improved by soaking mango stones in aqueous solutions of 100 ppm GA3 or Thiourea at 1 % for 24 hours before sowing.

Betalain estimation and callus induction in different explants of Bougainvillea spp.

The present study was carried out to investigate the in vivo betalain content in bract and leaf of some bougainvillea cultivars and to develop a reliable, rapid and efficient callus induction protocol. The maximum betacyanin content in bracts was recorded in the cv. Bhabha (2.68 mg/g FW) followed by cv. Rao (2.40 mg/g FW). The maximum betaxanthin content in bracts was recorded in the cv. Lady Mary Baring (1.27 mg/g FW). The maximum betacyanin content in leaf was recorded in the cv. Dr H B Singh (0.58 mg/g FW), while the maximum betaxanthin content in leaf was recorded in the cv. Bhabha (0.73 mg/g FW). The total betalain content in bract was estimated to be maximum in the cv. Bhabha (3.60 mg/g FW) followed by cv. Rao (3.36 mg/g FW). The total betalain content in leaf was highest in cv. Bhabha followed by cv. Dr R R Pal. Of the different treatments employed for callus induction on Murashige and Skoog’s (MS) medium using leaf explants in bougainvillea cv. Bhabha, the treatment comprising 6 mg/l 2,4-D recorded maximum induction coefficient (98.75%) and minimum days (8.50) was required for callus initiation. In case of internodal explants the induction coefficient was lower and more number of days was required for callus initiation. No callus induction was recorded on bract. Absolutely no callus induction was noted on the MS basal medium devoid of plant hormones (control). The maximum gain in callus biomass accumulation, in both the explants, in terms of fresh and dry cell weight was recorded in the callus cultured on MS medium supplemented with 6 mg/l 2,4-D. This treatment also resulted in lowest fresh and dry cell weight ratio in leaf and internodal explants. Wounding of leaf explants was found to be beneficial for accelerating the callogenesis process. The multiplication of callus was satisfactory on MS medium supplemented with doubled quantity of vitamins and 6 mg/l 2,4-D.

Determinación de ecuaciones alométricas para estimar biomasa y carbono en Pinus patula Schl. et Cham

En el Ejido Mariano de Matamoros, Tlaxco, Tlaxcala, se seleccionaron 25 árboles de Pinus patula Schl. et Cham., y se determinaron su biomasa y carbono en el estrato aéreo para ajustar el modelo Y=b*Xk, tomando como variable independiente (X) el diámetro normal (DN). Se obtuvieron muestras de cada uno de los siguientes componentes (fuste, ramas y follaje) de cada árbol, y en el campo se determinó el peso fresco, tanto de la muestra como del componente, Las muestras se llevaron al laboratorio para ser secadas y obtener su peso seco, para después estimar la biomasa total de cada árbol, usando para ello la relación peso seco: peso fresco de las muestras. Para determinar el carbono de los diferentes componentes se tomaron muestras de cinco árboles y fueron analizadas en el laboratorio, obteniendo así 52,21% de carbono en el follaje, 49,47% en las ramas y 49,26% en el fuste, de esta forma la concentración promedio por árbol fue de 50,31%. Para estimar la biomasa se ajustó y generó la ecuación B = 0.0357 * DN2.6916, y para estimar el carbono la ecuación ajustada fue CC = 0.021 * DN 2.6451, con los coeficientes de determinación para ambas de 0,98.

Effects of mixed rare earth fertilizer on yield and nutrient quality of leafy vegetables during different seasons

Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons (spring and autumn), the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.

Relationships between fresh weight, dry weight, ash free dry weight, carbon and nitrogen content for selected vertebrates

Top predators are relevant indicators of the ecological status of a system and can have a high impact on food webs. But top predators are difficult to include in network analyses because their biomass in ash free dry weight or carbon content is missing. Regression equations were determined for the relationships between fresh weight and dry weight, ash free dry weight, carbon and nitrogen contents respectively for six of the most abundant bird species in the Wadden Sea (Calidris canutus, Limosa lapponica, Haematopus ostralegus, Chroicocephalus ridibundus, Larus canus, Anas penelope) and harbor seals (Phoca vitulina). The relationships for all species were interpreted as linear through the origin. Carbon content vs. fresh weight ratios for birds ranged from 0.16±0.01 to 0.22±0.02. Carbon content vs. fresh weight ratio was 0.17±0.02 on average for harbor seals. This work highlights that the biomass of top predators was often over- or underestimated in previous studies. The determined conversion factors will be useful for future studies to generate more realistic food web models.

Effects of Plant Growth Regulator on Growth Traits in Wheat Seedlings under Different Salt Concentrations

To reduce the damage caused by salt stress on wheat, we studied the effects of plant growth regulator on growth traits in wheat seedlings under different salt concentrations by setting different salt concentrations. The results showed that the plant growth regulator had effects on leaf length, plant height, aboveground fresh weight, underground fresh weight and root-shoot ratio under 0.1, 0.2, 0.3 and 0.4%, respectively salt concentration, but the effects to improve growth traits of 0.2% salt concentration were most obvious. So studying effects of plant growth regulator on growth traits in wheat seedlings under different salt concentrations has a theoretical and practical significance in salt tolerance and wheat cultivation in saline alkali soil.

Ploidy Level and DNA Content of Erianthus arundinaceus as Determined by Flow Cytometry and the Association with Biological Characteristics.

Erianthus arundinaceus is not only an important germplasm resource for sugarcane breeding but also a potential bioenergy plant. Making clear the distribution of the chromosome ploidy of wild E. arundinaceus in china is the premise of the research and utilization of this species. Therefore, the objectives of this study were to determine the ploidy level and DNA content of the 55 E. arundinaceus accessions using flow cytometry and to identify the correlation between ploidy and phenotypic traits. Among the 55 accessions, four tetraploids and 51 hexaploids were identified. The four tetraploids originated from Mengma Yunnan, Shuangjiang Yunnan, Gaozhou Guangdong and Chengle Sichuan. The mean DNA content was 4.82 pg/2C for the tetraploid and 7.30 pg/2C for the hexaploid plants. The ploidy was negatively correlated with cellulose content and positively correlated (P<0.05) with plant height, stem diameter, leaf width, dry weight per plant, fresh weight per plant and hemicellulose content. However, ploidy was not correlated with leaf length, tiller number and the ratio of dry weight and fresh weight. This study will be useful for revealing the distribution of the ploidy of wild E. arundinaceus in Chin, traits markers analysis, and utilization of this species, such as cultivar improvement and sugarcane breeding in the future.

Effect of zinc and lead on the physiological and biochemical properties of aquatic plant Lemna minor: its potential role in phytoremediation

Plants have gained importance in situ bioremediation of heavy metals. In the present study, different concentrations of zinc (Zn2+) (0.5, 5, 10, 15, 20 mg/l) and lead (Pb2+) (1, 2, 4, 6, 8 mg/l) were used to evaluate metal tolerance level of Lemna minor. L.minor were exposed to metals for 4 days and tested for its dry to fresh weight ratio (DW/FW), photosynthetic pigments production and protein content. The oxidative damage was detected by measuring catalase activity. L.minor showed tolerance against Zn2+ and Pb2+ at a concentration of 10 and 4 mg/l, respectively. Among the metals, Pb2+ showed a significant toxicity at 8 mg/l. High concentration (20 mg/l of Zn2+ and 8 mg/l of Pb2+) of the metals displayed a considerable negative effect on soluble proteins (13 fold decrease with Zn2+ and 4 fold decrease with Pb2+) and photosynthetic pigments (twofold decrease with Zn2+ and onefold decrease with Pb2+) and lead to a consequent reduction in number of fronds. Further, the catalase was greatly increased (twofold decrease with Zn2+ and sixfold decrease with Pb2+) under metal stress. The results indicate that L.minor withstands Zn2+ and Pb2+ toxicity up to the concentration of 10 and 4 mg/l, respectively. Hence, the metal tolerant property of this plant shall be exploited for bioremediation of Zinc and Lead in polluted water. Further, the detailed and wide range of heavy metal toxicity studies should be done to reveal the possible use of this plant on large scale bioremediation purpose.

Growth parameter study in Camelina sativa, a potential biofuel crop, under in-vitro culture conditions

The present study was conducted with the aim to find the effect of in vitro culture conditions on growth parameters, viz. germination, growth vigour, cotyledon opening, true leaf emergence, plant water content, shoot fresh weight, dry weight and leaf weight ratio of Camelina sativa (cv Calena). It was found that there was no significant difference with respect to germination (almost 100%) in all the media (water agar, half MS and full MS) but the rate of germination measured as Timson index significantly differed. In water agar the rate of germination was 95.42% in full MS 86.9% and in half MS 83.33%. Emergence of true leaf and growth vigour was highest in full MS as compared to half MS and water agar. There was significant difference in rate of germination, cotyledon opening, true leaf emergence, plant water content, fresh weight, dry weight and leaf weight ratio in all media. Shoot length was maximum (4.5 cm) in MS medium with highest fresh weight and dry weight (0.35 mg; 0.023 mg) as compared to half MS (0.204 mg; 0.017 mg) and water agar (0.031 mg; 0.014 mg). When explants (hypocotyl, leaf segment, nodes and shoot tip) collected from in vitro seedlings were cultured in MS with 1-5 mg/l BAP, 4 BAP gave best response for shoot tip and nodal explants followed by other combinations in descending order (100%, 88%, 82%, 77%, 73% in 4 BAP, 5 BAP, 3 BAP, 2 BAP and 1 BAP respectively). Other explants responded by enlargement and curling with little or no callus and eventually turned brown and necrotic. The preliminary results obtained in the present study shows the in vitro response of Camelina sativa, which can be used further for in vitro abiotic stress studies and genetic manipulation studies.

Additive biomass equations based on complete weighing of sample trees for open eucalypt forest species in south-eastern Australia

The aboveground biomass and carbon stock of less commercialized Eucalyptus open forests of south-eastern Australia are not well-known due to a lack of accurate biomass equations for even the prevalent species in these forests. To improve biomass and carbon estimates of these forests, a total of 245 trees of 11 eucalypt species with DBH (diameter overbark at the breast height of 1.3m above ground level) up to 139cm and height up to 39m were destructively sampled across three broad study sites in north-central Victoria. Trees were sampled as the four aboveground components of lower stem, upper stem, crown, and dead attached stem and branch materials. All four components were weighed completely in the field. To determine the dry to fresh weight ratio for each of the four components, 90 of these trees were further subsampled for moisture content. General linear models were used to relate dry to fresh weight ratio to site, species and tree size and the parameters of the models were estimated through generalized estimating equations. The model-estimated dry to fresh weight ratios were used to convert fresh weight to dry weight for all biomass components of fresh weight sample trees. Using the derived dry weight data, two systems of nonlinear additive biomass equations for stem, crown and total tree biomass were developed for each of the 11 species, with DBH as the independent variable in one system and the combined variable of DBH and tree height in another. Residual error variances and approximate confidence bands containing about 90% of the observed data about the mean curve of predicted biomass were estimated and derived for all biomass components of each species. In addition to the species-specific equations, two sets of site-specific biomass equations were developed using pooled biomass data from each site regardless of species. These systems of additive biomass equations will improve the accuracy of biomass and carbon estimation of open eucalypt forests in south-eastern Australia.