Thermal,swelling and stability kinetics of chitosan based semi-interpenetrating network hydrogels

The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (W_UB) max., for the blend was 52.3 % whereas for the bound (W_B) the max., was 41.9 %. However, for sIPN hydrogel films, the W_UB water decreased (max. 21.0 %) where as the W_B increased (max. 52.0 %). The decrease in W_UB and increase in the W_B is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively.     

Micropropagation of Prunus scoparia,a Suitable Rootstock for Almond under Drought Conditions

Prunus scoparia is a wild deciduous shrub, usually living on dry calcareous soils of the rocky mountains and has been used as a grafting rootstock for domesticated almonds to provide drought resistance. In the current study, micropropagation ability of P. scoparia was investigated using cytokinin and auxin. Uniform nodal shoot pieces (3–5 cm in length) of seedlings were used as explants. The explants were disinfected with 10% sodium hypochlorite solution. For adventitious shoot induction and proliferation, Murashige and Skoog (MS) media containing 7.00 g/l agar and 30.00 g/l sucrose containing five concentrations of benzyl adenine (BA) (0.00, 0.50, 1.00, 2.00, and 4.00 mg/1) and also containing six concentrations of Thidiazuron (TDZ) (0.00, 0.50, 1.00, 2.00, 5.00, and 7.00 mg/1) were compared. For rooting, in vitro shoots (2–3 cm) were transferred into ½ MS medium supplemented with 30 g/l sucrose, 7.50 g/l agar, and different concentrations of IBA (0.00, 0.25, 0.50, and 1.00 mg/l) and NAA (0.00, 0.25, 0.50, and 1.00 mg/l). Based on the results obtained for shoot proliferation, only 2.00 and 4.00 mg/l BA and 2.00 mg/l TDZ concentrations generated shoots, while other treatments did not show shoot proliferation. Among the three treatments that generated shoots, the best results for shoot number, leaf number, and leaf color quality were observed in media containing 2.00 mg/l TDZ. Based on the results obtained for rooting, the effect of IBA concentrations on the rooting percentage, root number, and root length was significant. Among IBA concentrations, only 0.50 mg/l IBA induced rooting, while there was no rooting in the media containing other IBA concentrations. None of the NAA concentrations showed rooting. In conclusion, MS culture medium supplemented with 2.00 mg/l TDZ and ½ MS culture medium supplemented with 0.50 mg/l IBA are suggested for in vitro shoot proliferation and rooting of P. scoparia, respectively. The results presented herein could be used for in vitro selection and micropropagation of P. scoparia.     

Physico-chemical characteristics of apricot (Prunus armeniaca L.) grown in Northern Areas of Pakistan

In order to ascertain physico-chemical, functional and geometrical traits of apricot fruit from Northern Areas of Pakistan, six predominantly grown varieties namely, Alman, Habi, Khakhas, Mirmalik, Neeli and Shai were selected in this study. Proximate composition as crude fat (2.1–3%), crude protein (6.18–8.7%), crude fiber (11.85–13.6%), ash (9.45–12.1%) and total sugars (56.8–64.9%) were determined on dry weight basis. The data showed variations among the investigated parameters in all varieties. Functional properties of apricot fruit viz. ascorbic acid (67.39–90.94 mg/100 g), total phenolic compounds (4590–7310 mgGAE/100 g), total carotenoids (10.09–18.13 mg/100 g β-carotene) and antioxidant activity (56.84–82.33%) were also recorded. The data pertaining to mineral contents (mg/100 g) revealed K as the predominant element (2040–3000) followed by P, Mg, Ca, Na and Fe among all the tested samples. Furthermore, geometrical characters of apricot varieties were also determined as important sensory and technological attributes on fresh weight basis. The result from the present study showed that all the tested varieties are highly nutritious and rich in functional components.     

Evaluation of furrow fertigation and model validation on maize field

In new agricultural practices, joint application of water and fertilizer has been become common. Uniform distribution of fertilizer in soil and in plant growth duration is possible by this procedure. The main objective of this study was to investigate furrow fertigation management effects on distribution uniformity and runoff losses of nitrate in a cornfield, and validate a numerical fertigation model. A field experiment was carried out with seed corn at 12 experiments with a complete randomized block design during 2 years. Nitrogen requirement was determined by soil analysis and accomplished in four stages of the growth: before cultivation, in seven leaves, shooting and earring stages which first section (before cultivation) was applied by manual distribution and others by fertigation. Potash and super phosphate fertilizers (based on soil analysis) were sprayed on soil before planting. Water requirement was estimated by using class a evaporation pan multiplied by plant (Kc) and pan coefficients. Nitrogen fertilizer was solved in irrigation water and injected at the last minutes of irrigation. The results showed that fertilizer distribution uniformity of the low quarter (DU_LQ) ranged from 85.7% to 91.5% in first year, and 69.9% to 95.5% in second year. While water DU_LQ ranged from 74.1 to 98.2% in 2 years. Nitrate losses of surface runoff have ranged between 5.7 and 42.0% in first year according to the application time and the outflow flux. In second year, the nitrate losses decreased by adopting appropriate management based on the experiences of first year. The fertigation model was subsequently applied to the experimental data and results showed good agreement with field data.     

播期和密度对棉花叶柄和根系硝态氮含量的影响

为探讨大田棉花氮代谢随播期和密度的变化规律,选用华棉3109(G.hirsutum L.)于2014年在华中农业大学试验农场,采用裂区设计:播期(月-日)(S1,05-30;S2,06-14)为主区,密度(株·m-2)(D1,7.5;D2,9.0;D3,10.5)为副区,研究了硝态氮含量在主茎叶柄和根系的分布特点。结果表明:1)随生育进程推进,叶柄和根系硝态氮含量先升高后降低,初花期最高。2)主茎叶柄硝态氮含量随叶位变化,蕾期、初花期由上而下逐渐降低,第1叶最高;盛花期逐渐增高,第1叶和第4叶最高;不同生育时期棉花叶柄硝态氮含量在叶位间的下降幅度随播期推迟而降低,随密度增加先升高后降低。3)播期和密度对不同生育时期棉花叶柄和根系硝态氮平均含量的交互作用均显著,但播期和密度主效应影响不同:见花施肥前,随推迟播期,棉花叶柄硝态氮平均含量显著降低了42.9%,根系硝态氮平均含量显著升高了12.1%,增加密度对叶柄和根系硝态氮平均含量无显著影响。见花施肥后,随播期的推迟,叶柄硝态氮平均含量无显著性变化,初花期平均为5.05 mg·g-1,盛花期平均为2.62 mg·g-1;而根系硝态氮平均含量,初花期S1S2,盛花期S1S2;随密度增加,D1,D2与D3初花期叶柄和根系硝态氮平均含量均显著降低;盛花期叶柄硝态氮平均含量呈先升高后降低趋势变化,而根系硝态氮平均含量则与初花期相反,呈显著递增趋势。综上所述,晚播高密条件下,见花一次施肥后,推迟播期不改变棉花地上部叶柄硝态氮平均含量水平,适度增加密度有利于棉花叶柄维持较高的硝态氮含量,有利于为叶片氮代谢提供充足的底物。     

Salinity tolerance of earthworms and effects of salinity and vermi amendments on growth of Sorghum bicolor

Salinity is a major factor limiting irrigated agriculture in arid regions. Vermi amendments can be used for improving the fertility of salt-affected soils. Current study was aimed to find out the response of different earthworm species to soil salinity and to check the effects of salinity and different vermi amendments on growth of Sorghum bicolor under salt stress. Eight earthworm species were subjected to different salinity levels for 4 weeks. Various vermi amendments and salinity treatments were provided in a factorial combination to S. bicolor plants to see their effect on growth and biomass parameters. L. mauritii, E. incommodus and P. posthuma were found to be the most salt-tolerant species showing good survival and growth till soil EC_e value of 10.48 mS cm^?1. Results showed that salinity significantly decreased plant growth that was enhanced by the application of different vermi amendments. Maximum growth of S. bicolor was recorded when vermicompost and vermiwash were used together under both saline and non-saline conditions. The results showed that the application of vermi amendments improved nutritional balance of the soil, delayed salt-induced damage to the plants and supported their growth so can be helpful in increasing crop production on saline soils.     

The Bio-Functional Properties of Pigmented Cereals may Involve Synergies among Different Bioactive Species

This study was aimed at characterizing the anthocyanins and phenolics profile in different varieties of pigmented corn and wheat and in some of their milling fractions. Acid/ethanol extracts were used to assess total anthocyanins, overall antioxidant activity, the overall polyphenol profile, and for evaluating the inhibition of pancreatic α-amylase and of intestinal α-glucosidase. Both enzymes were inhibited in a dose-dependent manner by all extracts, but individual extracts had specific effects on each enzyme. Anti-inflammatory response was evaluated by using acid-free extracts and Caco-2 cells transiently transfected with a luciferase reporter gene responding to cytokine stimulation. The immune response of interleukin-stimulated cells decreased significantly in a dose-dependent manner in the presence of 20–50 μM/l anthocyanins from all grains extracts, again with a different efficiency. The inhibitory ability and the anti-inflammatory capability of these extracts are in most cases higher than in similar extracts from other sources, suggesting that activities in each extract may imply specific synergies between anthocyanins and other phenolics.

     

Effect of various phosphorus and calcium concentrations on potato seed tuber production

Although the effects caused in plants by the calcium (Ca)–phosphorus (P) interaction in calcareous soils are well documented, very few studies report on such effects in nutritive solutions or hydroponic cultivation. In a sand and perlite (1:1 volume) hydroponic system, effects of various P (21, 42, and 63 ppm) and Ca (120, 180, and 240 ppm) concentrations on potato tuberization were studied. A factorial experiment based on a completely randomized design with three replications was conducted. For maximum tuber yield and tuber number production, 21 and 42 ppm P was sufficient, respectively. Increase in P and Ca concentrations in nutrient solutions in early growing season resulted in an increase in shoot and root weight, leaf area, and shoot length linearly, but tuber yield and tuber number did not follow this trend. The maximum tuber specific gravity and total solid percent were also observed in 42 ppm P. The highest tuber number and tuber yield were observed in 120 ppm Ca concentration.