Rapid and Effective Methods for Breaking Seed Dormancy in Buffalobur (Solanum rostratum)

Abstract

The spread of buffalobur in China poses a serious threat to existing ecosystems, and control and eradication of this species have become increasingly important. Studies were carried out to ascertain the seed production, morphological characterization, dormancy behavior, and methods for breaking dormancy of buffalobur. The results showed that a single buffalobur plant could produce 1,600 to 43,800 seeds with an average weight of 3.0 mg. Average seed length, width, and thickness were 2.5, 2.0, and 1.0 mm, respectively. Newly ripened buffalobur seeds were innately dormant and exhibited combinational dormancy, which involves a hard seed coat (physical dormancy, PY), a partial dormant embryo (physiological dormancy, PD), and a dark requirement to germinate. PY of buffalobur seeds could be broken by dehusking or acid scarification by 14 M H2SO4for 15 min, with germination rates of 55 or 50%, respectively. PD was effectively broken by KNO3or gibberellic acid (GA3). The optimum concentration for KNO3was between 20 and 40 mM, which resulted in over 70% seed germination. When presoaked with GA3at 30 C in dark for 24 h, maximum germination (> 98%) was obtained at 2.4 mM, the corresponding germination speed (85%) and germination index (16) were also highest at this concentration. Synergistic effects were observed in seed germination when H2SO4and GA3were combined. The most rapid and effective combination in breaking dormancy was when the seeds were immersed in H2SO4(14 M) for 20 min and presoaked with 2.4 mM GA3for 24 h. Germination index for this combination was over 35, and 95% of the seeds germinated within 7 d. Knowledge gained in this study will be useful in increasing germination of buffalobur and facilitating further laboratory studies.

Effects of chemical treatments and environmental factors on seed dormancy and germination of shepherd's purse (Capsella bursa-pastoris (L.) Medic.)

“…Chauhan et al (2006b) found that the germination rate of Oriental mustard (Sisymbrium orientale) seeds increased in direct proportion to increasing concentrations of KNO 3 , although only up to 0.02 M, after which it decreased. Promotion and inhibition of germination at low and high concentrations of KNO 3 have previously been reported by Wei et al (2010) and Foley & Chao (2008), in different plants.…”

Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design

“…In this respect, seed soaking for 12-24 h is known to be an efficient means for improving the germination of Solanum species (Hayati et al, 2005;Ahmed et al, 2006), as it may remove seed germination inhibitors (Bewley et al, 2013). Similarly, applications of the plant growth regulator GA 3 or KNO 3 are efficient at releasing Solanum seeds from dormancy and stimulating germination (Hayati et al, 2005;Wei et al, 2010;Gisbert et al, 2011a). Light irradiation, which is an important regulator of seed germination in solanaceous species (Koo et al, 2015), has also been observed to be efficient at stimulating germination in S. torvum seeds.…”

“…This characteristic has even led to the proposed use of vegetative propagation to overcome the seed germination problem (Miceli et al, 2014). The breaking of dormancy, which is a common phenomenon among wild Solanum species (Taab and Andersson, 2009;Wei et al, 2010;Kandari et al, 2011;Tellier et al, 2011), and the enhancement of germination can be achieved using combinations of many different physical (e.g., seed soaking, manual scarification, cold stratification, heat shocks, light irradiation, and magnetic fields) and/or chemical (e.g., scarification with acidic or basic chemicals, plant growth regulators, and osmotic treatments) treatments (Finch-Savage and Leubner-Metzger, 2006;Bewley et al, 2013;Holubowicz et al, 2014).…”

Treatment of Solanum torvum seeds improves germination in a batch-dependent manner1

“…Similarly, applications of GA 3 or KNO 3 were also efficient for other Solanum species (Hayati et al 2005, Wei et al 2010, Gisbert et al 2011.…”