TITLE:
Development of Hydropriming Techniques for Sowing Seeds of Upland Rice in Uganda
AUTHORS:
Yoshihiro Nakao, Godfrey Asea, Minoru Yoshino, Nobuki Kojima, Hiroyuki Hanada, Kisho Miyamoto, Shin Yabuta, Rieko Kamioka, Jun-Ichi Sakagami
KEYWORDS:
Rice, Priming, Germination, Emergence, Seed
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.11,
October
19,
2018
ABSTRACT: Hydropriming
is one of the presoaking, seed priming technique that allows seeds to imbibe
water and go through the
first stage of germination but does not allow radicle appearance. After water
imbibition, seeds are dried to their original weight. This technique is used to
help crops overcome environment stress. This study aims to assess the
morphological traits of farmer’s seeds for developing priming treatments so as
to develop appropriate methods to maximize the effect of hydropriming. We
collected farmer’s samples of rice sowing seeds grown indifferent regions of
Ugandan. For each sample, distribution of the seed density in percentages was
calculated. Secondly, germination tests as per seed density levels and as per
farmer’s seed samples were conducted for deciding appropriate priming
treatment. Finally,
wooden boxes experiment was conducted to confirm priming effects. As the result,
it was observed that the difference in seed density levels affects the quality
of farmer’s seeds, as observed in the case of NERICA4. If the radicle appears
during soaking period, the newly developed radicle dies during the seed drying
process in the hydropriming treatment. Seed germination was observed after 24 h
of sowing at room temperature, even at a seed density level of 1.17, which is
vigorous for germination. Consequently, farmer’s seeds were soaked for 24 h to
promote water absorption and activate metabolic pathways and to avoid germination
failure when seeds are dried to their initial weight. After hydropriming
treatment, plant growth
was improved. Alternatively, significant difference was not observed in the
mean emergence time between hydroprimed and unprimed seeds. These results
suggest that priming the seeds by soaking for 24 h and drying to their initial
weight considerably affects initial growth after emergence under dry soil
condition.