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Plant biostimulants have received increasing attention in recent years because of their positive effects on crop performance and contribution to agro-ecological sustainability. The aim of this study was to determine the influence of betaine and chitin treatments, alone and in combination, on lettuce plants by changes in the morphology and physiology of plants exposed to regulated deficit irrigation (RDI). Plants were subjected to full irrigation (FI; no water deficiency treatment, field capacity >70%) and RDI (field capacity <50%) conditions until the end of each experiment. We recorded plant yield–related traits, net photosynthesis, and water use efficiency (WUE) values weekly for 4 weeks and carried out three individual experiments to assess the efficacy of biostimulant and irrigation treatments. Betaine (0, 50, and 100 mm/plant) was foliar-treated every 2 weeks during Expt. 1, whereas chitin (0, 2, and 4 g/kg) was applied to the soil at the beginning of Expt. 2. We then applied the optimal concentration of each chemical alone or in combination to the plants as Expt. 3. Compared with negative control, the application of 50 mm betaine and 2 g/kg chitin significantly increased leaf area (LA) per plant by 48.5% and 25.6%, respectively. Furthermore, 50 mm betaine and 2 g/kg chitin treatment showed a clearly protective effect in RDI plants, enhancing their total fresh weights by 26.10% and 75.0%, respectively, in comparison with control. Comparing WUEyield and WUEbiomass, chemical-treated plants had higher values than control. Betaine (50 mm) or chitin (2 g/kg) treatments alone significantly elevated LA, fresh shoot weight, total fresh and dry weights, net photosynthesis, and WUE values, and boosted the water stress tolerance of lettuce under RDI compared with controls. However, a combined treatment of 50 mm betaine and 2 g/kg chitin did not increase the levels of all yield traits under RDI compared with individual chemical treatment. Most leaves appeared healthy, green, and had visually less leaf chlorosis when treated with chitin or betaine under RDI compared with untreated plants subjected to RDI. Our study indicates that applying betaine and chitin improves plant performance against water supply limitations and highlights their potential for the sustainable production of lettuce.
Research on the restorative benefits of nature primarily has focused on the spiritual benefits of wilderness areas, but other areas, such as cities, have not been studied. Horticultural activities have the potential to promote spiritual health, but most participants are not aware of this benefit. To improve this situation and to increase evidence of the benefits of therapeutic horticulture, this study suggests treating plant parables as trigger cues, which would allow an approach to interaction with plants through metaphysical imagination, resulting in an improvement in spiritual health from horticultural activities. The purpose of this study was to understand participants' beliefs of the spiritual benefits of horticultural activities, and to see if these beliefs were enhanced after reading plant parables. This study surveyed subjects with different horticultural backgrounds, and measured their opinions regarding belief in the spiritual benefits of horticultural activities, before and after reading the parables. The results indicated that before reading the plant parables, neither group of subjects with different horticultural backgrounds agreed with the spiritual benefits of horticultural activities; however, after reading the plant parables, the belief of participants with formal horticultural education backgrounds increased significantly (P ≤ 0.001). The increase was not significant in subjects without formal horticultural education backgrounds.
The inheritance of resistance to neck rot, incited by Botrytis allii Munn, was studied in four crosses between resistant and susceptible bulb onion (Allium cepa L.) lines, one cross between two resistant lines, and one cross between two susceptible lines. Using tests of excised scale pieces inoculated with a spore suspension and incubated in plastic boxes at 20C for 6 days, parents, F1, F2, and backcrosses were assigned disease indices (DI) derived from infection severity scores of individual bulbs. Generation means and frequency distribution of DI indicated that inheritance was quantitative and mostly additive with a small amount of dominance for susceptibility. Estimates of gene effects using a three-parameter model also indicated that additive effects predominated, with some dominance and no epistasis. Broad-sense heritability estimates ranged from 42% to 63% in the resistant x susceptible crosses.
Analysis of parents and progeny generations of bulb onion (Allium cepa L.) crosses among parents with differing content of soluble solids (SS) and pyruvic acid (PA) showed that SS and PA are expressed and inherited in a quantitative manner. Distribution of SS and PA in both parents and progenies covered a range of values. Generation means, frequency distributions, deviation from midparent value, and estimates of gene effects all indicated that inheritance of SS and PA was additive, except for small deviations from the additive hypothesis in several individual backcrosses. Estimates of broad-sense heritability ranged from 48% to 53% for PA and 8 % to 56 % for SS. Phenotypic correlations between PA and SS estimated from the F2 generations of two crosses, were moderate and positive (r = 0.50 and 0.42).
An in vitro method for obtaining bamboo mosaic virus (BaMV)-free plantlets of Bambusa oldhamii Munro was developed. BaMV-free meristems were incubated on MS basal medium supplemented with 0.45 μm thidiazuron (TDZ) to induce the development of multiple shoots. Multiple shoot proliferation was higher in stationary liquid culture than on semisolid medium. Cytokinin was the key component for inducing proliferation, and TDZ was the stable and effective cytokinin for proliferation in long-term subcultures. Multiple shoots rooted after 1 month in MS basal medium containing 10.74 to 26.85 μm α-naphthaleneacetic acid with a rooting efficiency of 83%. Healthy, well-developed plantlets were transferred to soil in pots and raised in a greenhouse. Those plants derived from tissue culture were more vigorous than the ones derived from the traditional in vivo vegetative propagation method, air layering. The tissue culture-derived plants could produce the culms after 15 months. Fifteen of 38 plants flowered 2 years after being transplanted to the field.
It studies the changes of endogenous hormones and polyamines in cytoplasmic male sterile non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis Makino var. communis Tsen et Lee). Results showed that the microspore was prone to being sterile when there were lack of IAA, GA and polyamines, especially Put and abundant with ZRs and ABA in the anther. The imbalance of IAA/ZRs also easily caused the anther sterile.
A xylem mutant (vse) was isolated from a Bambusa edulis (Odashima) Keng plantlet following vegetative micropropagation and subculture for 7 consecutive years and induced to proliferate in medium supplemented with 0.1 mg·L-1 (0.5 μm) thidiazuron (TDZ) and to develop roots in medium supplemented with 5 mg·L-1 (26.9 μm) α-naphthaleneacetic acid (NAA). Subsequent investigations comparing the growth habits of mutant plantlets with those of the wild type indicated that the growth of the former was retarded in a greenhouse. Several morphological abnormalities were observed in the vse mutant: it had thinner stems with fewer trichromes on the surface; the xylem vessels were smaller in diameter and contained crystal-like structures in the pith; the leaves were shorter and narrower with a sharp leaf blade angle; the roots were thinner and contained fewer xylem cells. The cation concentrations of both the mutant and wild type were similar in the in vitro analysis, except for those of iron and potassium, which were lower in mutant leaves in vivo. In 2-month-old mutant plants, iron chlorosis was observed on young leaves and a potassium deficiency was observed on older leaves. After 1 year of growth in the greenhouse, all of the wild-type plants had survived, but only 27% (16/60) of the mutant vse plants were alive.
Camellia flowers are highly prized for their beauty worldwide and are strongly symbolic in many cultures. A new interspecific hybrid cultivar, Camellia ‘Maozi’, generated by crossing Camellia pubipetala with C. japonica ‘Dahong Mudan’, exhibits strong hybrid vigor and has small flowers with a rare light tone of purple. In southwest China with a subtropical monsoon climate, young Camellia ‘Maozi’ trees flush shoots three times in spring, summer, and autumn, with an average annual growth of 12.9 cm. Adult trees flush once a year. Floral bud formation occurs in late April and early May. Camellia ‘Maozi’ flowers are sterile with no fruits and seeds produced. While an individual flower wilts 4–8 days after opening, the blossom can last 1–3 months. Frost damage can be found in young leaves when temperature drops to 4–7 °C. Under direct sunlight with temperatures of 37–39 °C lasting for more than 2 days, young leaves can turn yellow on their edges. Its primary diseases include sooty mold, shoot tip blight, and peony leaf tip blight. Its primary insect pests are tea green leafhopper (Jacobiasca formosana) and tea aphid (Toxoptera aurantii). Rooting of stem cuttings occurs directly from stems, mostly without callus development. Two hours of treatment with 500 mg·L−1 indole-3-butyric acid and rooting in a mix of latosolic red soil and vermiculite (2:1 v/v) resulted in high rooting rate and quality of aboveground growth. Grafting can be carried out from May to September, while survival rate and new shoot length are highest in July. The most compatible rootstock is C. oleifera, followed by C. polyodonta. The results of this study are of value for understanding the reproductive biology of Camellia ‘Maozi’ and further disseminating it as a new cultivar for camellia collection.