Showing 3 results for Vigor
M. Jamshid Moghaddam, S. S. Pourdad,
Volume 10, Issue 2 (7-2006)
Abstract
To evaluate seed germination and seedling growth of safflower in moisture stress, germination of 15 genotypes at four water potential levels (ψ: 0, -0.4, -0.8 and –1.2 Mpa) was tested by Polyethylene glycol (PEG6000). Maximum germination (Gmax), germination rate index (GRI), time length to reach 50% germination (T50), rootlet length (RL) and shootlet length (SL) were investigated. Effects of water potential levels and genotypes were significant for all the characteristics studied. Minimum water potential for germination was estimated between –1.17 and –1.59 Mpa in Goshkhani and LRV-51-51 genotypes, respectively. Different responses to moisture stress were found for rootlet length. In lower potential levels, seedlings had longer, weaker and thiner rootlets in comparison to the zero water potential (control). An increase in stress to –1.2 Mpa led to a severe reduction in rootlet elongation. All stress levels decreased GRI and SL, while potentials lower than –0.4 Mpa decreased Gmax. With a decrease in water potential from 0 to –0.8 Mpa, the T50stage was delayed three-fold compared to the control. Exotic genotypes had longer T50 stage than Iranian genotypes. The highest GRI was related to three Iranian genotypes LRV-51-51, Varamin 295, and Isfahan local, and the lowest was related to CW-74 exotic genotype. Some of genotypes were evaluated for seed yield, oil yield and seed oil percentage under rainfed condition in 2004-05. The highest oil yield average belonged to two exotic genotypes PI- 537598 and Lesaf (326.4 and 313.9 Kg/ha, respectively) and the least was related to Zarqhan 279 Iranian genotype (133.2 Kg/ha). Negative and significant correlation was observed between seed oil percentage and GRI in the 0, -0.8 Mpa potential levels. According to the results, the existing genetic variation for germination parameters can be used for genetic improvement of seed early vigor in safflower.
M. Saeidi, A. Ahmadi, K. Postini, M. R. Jahansooz,
Volume 11, Issue 1 (4-2007)
Abstract
Soil moisture is one of the most important determinants of plant’s seed germination, emergence and finally yield formation in arid and semi-arid zone (e.g. IRAN). In such a situation, the selection of a cultivar resistant to drought is the most important task. In this regard, a research at three levels (Farm, Greenhouse, Laboratorial) was conducted to study 10 genotypes with three improved background including: Improved Indigenous(II) genotypes (Sardary, Roushan, Omid), Improved Indigenous Foreign Crossed (IIFC)(Azadi, Falat, Qods) and four Indigenous lines (IL)(5593/2-3, 6452-6, 5806-3, 7007/2-6). On the basis of our data with decrease of osmotic potential, seed vigor with high speed and slope in different genotypes decreased. In -0.8 MPa level of osmotic potential, Omid, Azadi and 5593.2-3 genotypes had the highest and Sardary, 5806-3 and Falat genotypes had lowest seed vigor. In -1.6 MPa level of osmotic potential seed vigor of all genotypes severely decreased and in this level of osmotic potential, no significant difference was observed among genotypes. The greater correlation between seed germination, vigor and emergence percentage in farm situation was obtained but the correlation between all germination characteristics in laboratory and farm situations with yield was not significant. Orthogonal analysis shows that II genotypes have greater seed vigor in comparison with other groups of genotypes, but did not show any significat difference among the three groups. The percentage and rate of germination.
F Ahmadloo, M Tabari, A Rahmani, H Yosefzadeh,
Volume 13, Issue 48 (7-2009)
Abstract
This research was carried out to improve the growth and performance of Arizona cypress (Cupressus arizonica) and Medite cypress (C. sempervirens var. horizantalis) seedlings in different combinations of organic matter in nursery of Koloudeh, located in Amol city (north of Iran). Seeds in plastic pots were sown as a completely randomized design (RCD) with four replications at different soil treatments including: T1) nursery soil (control), T2) control soil: cattle manure (5:1), T3) control soil: decomposited litter (5:1), T4) control soil: cattle manure: decomposited litter (5:1:1). The results after one year showed that the seedlings of both species grown on T4 obtained the greatest shoot height, collar diameter, seedling Vigor Index, shoot dry weight, root dry weight, total dry weight and seedling Quality Index (QI) among all the soils examined. The response of most attributes to soil was better in Cupressus arizonica than in C. sempervirens. It is concluded that organic matter caused the increase of growth and biomass of seedlings in both species. It can be proposed that in order to enhance the performance and improvement of Quality Index of seedlings in nurseries, the status of physico-chemical of soil-media should be seriously evaluated.
