PHYSIOLOGICAL STUDIES ON GERMINATION AND GROWTH OF OCHNA SHRUB A. GERMINATION OF THE QUICK DETERIORATED SEEDS OF MICKEY MOUSE (Ochna serrulata Hochst) PLANT.

Abstract

This investigation was conducted under shade at the nursery of AlZohriya Garden, Hort. Res. Inst., ARC, Giza, Egypt, during 2017 and 2018 seasons, to improve the germination of the quick failure seeds of Mickey Mouse plants (Ochna serrulata Hochst.) by sowing its depulped seeds in different times (directly after collection or after collection by 12, 24 and 48 hr.) and soaking them for 0, 12, 24 and 48 hr in 1 ml/l Lena-tonik solution (a commercial liquid plant growth regulator consisted of 1 g/l Na-5-nitroguaiacholate + 2 g/l Na-ortho-nitrophenolate + 3 g/l Na-para-nitrophenolate). The effect of the interaction between sowing time and soaking in Lena-tonik solution was also studied. The results indicated that the highest percentage of germination was obtained by sowing after 12 hr. from seed collection, as this treatment significantly increased the mean of this trait to 90 % in both seasons over all the other sowing times. Delaying sowing time to either 24 or 48 hr. significantly decreased germination percentage, while soaking the seeds in 1 ml/l Lena-tonik solution for any period raised germination percentage to 100 % regardless of the sowing time. The shortest time to either 100% germination velocity (G.V.) or 50 % mean germination rate (M.G.R.) was also achieved by planting the seeds after 12 hr. from harvest and by soaking in Lena-tonik solution. Likewise, the best results of germination rate index (G.R.I.), vigour index (V.I.), seed viability (S.V.) and plumule length were recorded as well by the previously mentioned two treatments, with the superiority of combining between them (sowing after 12 hr from seed collection + soaking in Lena-tonik solution at a concentration of 1 ml/l), as this combination gave in general the best germination results. Similarly, were those results of seedling growth characters (seedling length, No. leaves/seedling, root length and top growth and roots fresh and dry weights). Planting the seeds after 12 hr. from harvest scored also the highest concentration of chlorophyll a and b in leaves of the resulted seedlings, whereas planting at the other times gave concentrations closely near together. The opposite was right regarding the total soluble sugars content. Carotenoids concentration, however, was gradually increased with elongating sowing time. Soaking the seeds before planting in Lena-tonik solution slightly improved the previous constituents. The effect of the interaction between treatments fluctuated with few exceptions. From these results, it can be recommended to sow Ochna serrulata seeds after soaking them in 1 ml/l Lenatonik solution for 12 hours in order to attain better germination and higher quality of the seedlings produced.