Seed priming for increased seed germination and enhanced seedling vigor of winter rice

Abstract

Low seed emergence rate, poor seedling growth and low survival rate of winter rice due to cold spell are very common in Bangladesh. Pre-sowing seed priming could be a viable approach to overcome this problem. A laboratory screening of different priming agents was conducted at the Agro Innovation Laboratory, Department of Agronomy, Bangladesh Agricultural University in November 2018. The experiment comprised two factors. Factor A includes five rice varieties, namely i) BRRI dhan28 ii) BRRI dhan29 iii) BRRI dhan36 iv) BRRI dhan55 and v) Hybrid SL-8H; factor B includes 22 seed priming methods comprised different concentrations of NaCl, KCl CaCl2, CuSO4, ZnSO4, Na2MoO4, PEG and control (no priming). The experiment was laid out in a completely randomized design (CRD) with four replications. A positive influence of seed priming on seed emergence rate (%), germination time, seedling vigor and seedling growth (length and dry matter) was evident from this study. Among the priming agents, KCl and CaCl2 performed best; while priming with NaCl, Na2MoO4 and PEG showed no advantages over no priming for germination rate and seedling vigor & growth indices. In conclusion, pre sowing seed priming approach can be explored as a viable tool for increased seed germination and better seedling growth of winter rice under stress condition.

Seed priming with sodium nitroprusside enhances the growth of peanuts (Arachis hypogaea L.) under drought stress

“…Germination rate, germination time, and root length of seedlings are critical for plant growth rate under stress conditions (23). Seed priming, as evidenced by several reports, increases the tolerance of plants when exposed to stress.…”

Plants make smart decisions in complex environments

“…Some vigor indexes also consider a calculation that includes germination rate and seedling length. 30,45 In this case, high vigor also depends on seed's decision for fast reserves mobilization and allocation to elongation of hypocotyl and root axis.…”

“…Rice seeds had increased vigor when primed with specific salts like CaCl 2 and KCl, and the increased vigor in rice resulted from both faster germination and faster seedling growth. 45 At field conditions, seedling vigor should be observed with care. Cotton seedlings expressed reduced vigor because they had low rate of shoot growth while they decided to favor root growth for some days; the measurable vigor was lower when only shoot was being considered, but at harvest, they had similar productivity because their root capacity was stronger and compensated the low vigor observed in the early stage.…”

“…When planted, primed seeds have increased germination rate, seedling vigor, and improved performance under stress. 45,46 As alternative interpretation, a primed seed makes initial decisions preparing to germinate in the environment with controlled conditions (moisture, osmotic potential, temperature, light, and nutrients); however, when the process is interrupted and the seed is later planted in a different environment, its metabolism is still influenced by the decisions that had been made in the priming environment.…”

“…Rice seeds were primed with several chemical and hormonal agents and germinated faster under chilling temperature. 43,45 In other words, the rice seeds germinated under chilling temperature following decisions made under the priming conditions. The priming treatments were still influencing the plant's decision at the seedling stage, but to a lesser extent.…”