Khoshkharam M.

M. Khoshkharam, M.H. Shahrajabian, W. Sun, Q. Cheng

ABSTRACT. Allelopathy is the direct influence of chemical released from one plant on the development and growth of another plant. The trial accomplished in seed technology laboratory of Faculty of Agriculture, Islamic Azad University of Isfahan, in 2018. A factorial layout within completely randomized design with four replications was used. Treatments included plant organs extract (leaf, stem, root and total plant), and different tobacco extract densities includes four levels of 0%, 25%, 50% and 100%. Control treatment (0% of tobacco extract) had obtained the highest value of germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. The maximum germination rate, germination percentage, coleoptiles weight, radicle weight, radicle length and coleoptiles length was related to extract of stem extract which had meaningful differences with other treatments. Both radicle and coleoptile length decreased with increase in concentration of tobacco extract. Tobacco extract has negatively effects on corn seeds by decreasing the germination rate. Tobacco may increase the presence of secondary metabolites, such as alkaloids, all of which may have different effects on seed germination percentage. The highest germination percentage (91.91%), coleoptile weight (0.046 mg), radicle weight (0.0161 mg), radicle length (7.24 mm), and coleoptiles length (6.45 mm) was related to interaction between control treatment (0% of extract) and stem extract. It is concluded that the extract of Nicotiana tabacum had both inhibitory and stimulatory effects on seedling growth of Zea mays.

Keywords: radicle length; radicle weight; organ extract; coleoptile length; coleoptile weight.

M.H. Shahrajabian, M. Khoshkharam, W. Sun, Q. Cheng

ABSTRACT. Fennel is a plant belonging to the Apiacea (Umbelliferae) family, and used by humans for a long time for medicinal purposes. In order to evaluate the influence of different materials on germination and seedling growth of three cultivars of fennel, an experiment was conducted in 2018. The cultivars of fennel were Isfahan, Yazd, and Shiraz in main plots, and three materials including 100% soil, 50% diatomite + 50% soil, and 100% diatomite in subplots, were analyzed in a split plot experiment based on a randomized complete block design (CRBD) with three replications. The highest total germination percentage, coefficient of velocity of germination, epicotile length, fresh epicotile weight and dry epicotile weight was related to Isfahan. The maximum speed of germination, mean germination time, fresh length and dry leaf weight was achieved in Shiraz cultivar. The higher values of total germination percentage, speed of germination and mean germination time were related to 100% soil, while application of 50% of soil + 50% of diatomite had obtained the maximum values of radicle length, epicotile length, fresh epicotile weight, dry leaf weight and dry epicotile weight. The maximum values of coefficient of velocity of germination and fresh leaf weight was achieved in application of 100% diatomite. It seems that application of 50% soil + 50% diatomite and Isfahan and Shiraz cultivars have a great potential of seed germination of seedling growth.

Keywords: mean germination time; fresh epicotiles; germination percentage.