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Abstract
Individual Egyptian apricot (Prunus armeniaca L.) seedlings differed considerably in their response to 87 and 174 mm NaCl in nutrient solution supplied to roots. Wilting and/or necrosis of leaves were indices of sensitivity and survival. Damage occurred sooner, and more plants were affected at 174 mm salt. Some seedlings survived longer than others at both levels of NaCl. Root systems were reduced with prolonged treatment and some root death appeared to occur. Root damage occurred in some plants before toxicity symptoms appeared on leaves. Attempts to identify further apricot germplasm with improved tolerance to salinity appear warranted.
Abstract
Red and yellow mature fruit color in Capsicum pubescens is controlled by a single gene with yellow (y) recessive to red (y +).
This investigation was carried out on 13-year-old Valencia orange trees [Citrus sinensis (L.) Osbeck] budded on five different rootstocks. Heat unit accumulation (temperature above 12.5 °C) for fruits worked on the various rootstocks were calculated from full bloom to maturity stage. Valencia fruits on Troyer citrange (C. sinensis × Poncirus trifoliata) and Carrizo citrange (C. sinensis × Poncirus trifoliata) rootstocks matured earlier when compared to those growing on Cleopatra mandarin (C. reticulata Blanco), Volkamer lemon (C. volkameriana Ten. and Pasq.), and sour orange (C. aurantium) rootstocks. The results showed that the Valencia fruits, regardless of rootstock, could be stored for different periods under different conditions. However, in order to avoid degradation in fruit quality, storing periods should not exceed 21, 60, and 120 days under room conditions (25 °C and RH 25% to 35%), 4 °C (RH 80% to 85%), and 8 °C (RH 80% to 85%); respectively.
Nigellia sativa L. plants were fertilized with different rates of NPK fertilizers and sprayed with the growth regulators BL-2142 at 0, 250, 500, and 1000 ppm, CCC at 0, 500, 1000, and 1500 ppm and Multiprop at 0. 12.5, 25, and 50 ppm.
The results indicated that both of NPK fertilization and growth regulator treatments enhanced the plant growth in terms of stem diameter, branch number and herb dry weight. Also, these treatments caused early flowering, increased fruit number and seed yield compared to the control plants.
The interaction between NPK fertilization and growth regulators had a synergistic effect. The highest seed yield was obtained when the plants received 200, 100, and 25 kg/feddan (feddan = 4200 sqm) of urea, calcium superphosphate and potassium sulphate, respectively and sprayed with CCC at 500 ppm.
Nigellia sativa L. plants were fertilized with different rates of NPK fertilizers in combination with the growth regulators, BL-2142, CCC and Multiprop sprayed at varied concentrations.
Fertilization and growth regulators increased the volatile and fixed oil content in the seeds. The photosynthetic pigments in the leaves, the reducing sugar and the total carbohydrate contents, N, P, and K uptake in the herb were also increased.
The interaction between fertilization and growth regulators had a synergistic effect on increasing the volatile and fixed oil percentage and yield, the photosynthetic pigments, N, P, K uptake. The highest volatile oil yield was found when the plants received 100, 200 and 50 kg/feddan (4,200 sqm) of urea, calcium superphosphate and potassium sulphate, respectively and sprayed with 500 ppm BL-2142, 1000 ppm CCC or 12.5 pm Multiprop. The volatile oil, fixed oil yield and seed yield were highly and significantly correlated with each other.
Abstract
Inheritance of resistance to tomato yellow leaf curl virus (TYLCV) was studied in the interspecific crosses Lycopersicon escutentum Mill. cv. UC 82 x Lycopersicon cheesmanii ssp. minor (Hook) C.H. Mill. LA 1401, and Lycopersicon esculentum cv. VF 145-B-7879 x Lycopersicon hirsutum Humb. and Bonpl. LA 386. Genetic populations were artificially inoculated with TYLCV prior to transplanting, and were later evaluated under field conditions. Reaction of parents, F2 and F3 plants, and backcrosses of resistant F2 plants to UC 82, indicated that resistance derived from L. cheesmanii seems to be recessive. Narrow sense heritability (NSH) was 0.44. Reaction of parental F1, F2, and backcross plants indicated that resistance derived from L. hirsutum is dominant and controlled by more than one gene.
Peppermint (Mentha piperita), sweet basil (Ocimum basilicum), and coriander (Coriandrum sativum) are important medicinal plants in the pharmacological industry. These plants are produced in commercial scale but their seeds exhibit low germination percentages under favorable germination conditions. Enhancing seed germination is thus crucial for improving the production of these plants. The influence of gibberellic acid (GA3), indole-3-acetic acid (IAA), indol-3-butyric acid (IBA), and naphthalene acetic acid (NAA) on seed germination of the three plants were investigated. The seeds were soaked in each plant growth regulator at 50, 100, and 150 mg·L−1 for 24 hours at 25 ± 2 °C. Seed germination was checked daily for 20 days and germination parameters including final germination percentage (FGP), corrected germination rate (CGRI), and number of days lapsed to reach 50% of FGP (GT50) were recorded. The phosphorus and protein contents were determined in germinated seedlings on day 21 of culture. All plant growth regulators enhanced seed germination as compared with control. However, GA3 improved seed germination more than IAA, IBA, and NAA. GA3 at 100 mg·L−1 significantly increased the FGP from 22.3% and 33.3% (control) to 74% and 65.6% for peppermint and sweet basil, respectively. Low concentration of GA3 at 50 mg·L−1 increased the FGP for coriander from 27% to 52.3%. GA3 also increased CGRI, GT50, phosphorus, and protein contents in germinated seedlings as compared with control. Seeds of peppermint, sweet basil, and coriander possess a physiological dormancy that could be elevated by GA3 presowing treatment. This study established a successful methodology for optimizing seed germination to satisfy the demand for the medicinal parts of these plants in the pharmacological industry.
This work studied the micropropagation of fegra fig (F. palmata Forssk.) during which we experienced the incidence of shoot-tip necrosis (STN). STN was evident during the shoot elongation stage, which was regenerated on Murashige and Skoog (MS) medium supplemented with 2 mg/L 6-benzylaminopurine. To alleviate SNT, we conducted a series of experiments and supplemented the medium with calcium chloride (40, 80, and 120 mg/L), ascorbic acid (50, 100, and 150 mg/L), silver nitrate (1, 2, and 3 mg/L), and boric acid (9.3, 12.4, and 15.5 mg/L). Results showed that all the treatments controlled STN at varying levels, and supplementation of medium with 3 mg/L silver nitrate reduced the incidence of STN from 80% to 24%. The regenerated shoots were rooted on the same medium with incubation of cultures in the dark for 3 weeks and subsequent 4 weeks of incubation under 16/8-hour light/dark photoperiod. The growth parameters (number of shoots and roots, length of the main shoot and root, fresh and dry weights), photosynthetic pigments (chlorophylls and carotenoids), and relative water content of plantlets were restored with the application of 3 mg/L silver nitrate to the medium. Incubation of cultures initially in the dark followed by 16/8-hour light incubation facilitated axillary shoot elongation. On the basis of our findings, it is recommended to culture the regenerated axillary shoots of fegra fig onto MS medium containing 3% sucrose, 1.5 mg/L activated charcoal, and 3 mg/L silver nitrate to manage STN effectively.