Results
Seed water content after equilibration in the different conditions tested ranged from 8.9 to 21.2% fw (Table 1). Data are shown without differentiation of colors as there were no significant differences. There were also not significant differences between the water
contents reached after equilibration at 5 and 20℃ at 60% and 90% RH, and they were always significantly different to the ones obtained at 35℃.
Dormancy release
S. diclinis seeds showed strong dormancy immediately after harvesting, time 0, ranging the initial germination percentages from 6 to 13% (Fig. 2). Black seeds (13% germination) showed less initial dormancy than red and grey seeds (7 and 6% germination, respectively), not being the differences statistically significant (P >0.05).
Germination increased along time in all conditions of temperature and relative humidity; however, differences in the dormancy release rate were observed. Seeds stored at higher temperature lost their dormancy faster than those stored at lower ones, and this could be observed at the two RH studied (Fig. 2). It took around 40–70 days of storage at 35℃ to reach 90% germination, more than 140 days at 20℃, and 90% germination was not achieved at 5℃ after 400 days of essay. Moreover, seeds equilibrated at the highest relative humidity (60% RH, 11.53–12.59% wc) showed deterioration when stored at 20 and 35℃, and the germination percentage decreased towards the end of the storage period. As expected, ageing was faster in seeds stored at higher temperatures, and by 140 days at 20℃ and 98 days at 35℃, when equilibrated at 60% RH, germination started being reduced. This viability loss was confirmed by the patchy pattern of embryos after staining the non-germinated seeds with tetrazolium.
The linear regressions G (probit) = a + b time (days), for seed colors were compared
for each storage condition, and no significant differences were found both for slope and
intercept, therefore data from the three colors were used as replicates of the same condition.
For each storage temperature the resulted linear regression at each RH were compared
and significant differences were found in the slopes (P values were 0.004, 0.000, and 0.003
for 5, 20 and 35℃, respectively). Therefore, regressions were estimated for each storage
condition (Fig. 3, Table 2), with R2 between 0.66 and 0.91. The time required to totally
overcome the dormancy (100% germination) was calculated from the equations, values
being lower for higher temperature and relative humidity of storage (Table 2). Slope values
(DRR, probit/day) were higher when storage occurred at 60% RH than at 33% RH. So,
DRR was expressed against temperature independently for each RH condition (Fig. 4). All
slopes were positive and the point at which the line intersected with the temperature axis
gave the base temperature (Tb) for dormancy release for each RH: 1.6 and 2.7℃, for 33%
RH and 60% RH, respectively (Table 3).
With these Tb values it was possible to calculate the thermal time accumulated during
storage at each condition. The increase in germination on a thermal time scale was separated
into six distinct groups according to the storage conditions (Fig. 5, Table 4).
Dormancy release in response to thermal time was dependent on temperature and RH.
Dormancy release per day and ℃ was faster at 60% RH than at 33% RH (Fig. 5): for each
temperature, pair comparison of slopes showed significant differences (P >0.05). At a
temperature close to the Tb, 5℃, and high relative humidity, 60%, the dormancy release
rate per ℃ and day was also faster, although a higher fraction of the seeds stayed dormant
at the end of the study.
Ageing of non-dormant seeds
The average initial germination percentage at the start of the experiment of seeds of the
three colors was 96% (Table 5, Fig. 6); i.e. the seeds had lost their primary dormancy after
previous storage. Avrami parameters were calculated for those conditions and colors for
which their viability loss was higher than 15%, ruling out the rest of the cases because of
not being sound to calculate the parameters. The conditions for which the Avrami equation
was fitted were: 20℃—90% RH; 35℃—60%, 35℃—90% RH; and 5℃—90% RH only
for red seeds. For the cases with a germination percentage of 0%, the value was replaced by
0.5%, to proceed with the calculations.
Temperature and relative humidity affected longevity, being seed deterioration faster in
storage at high temperature and relative humidity (Fig. 6). In only 3–8 days, 50% of
viability was lost (P50) at 35℃—90% RH, whereas it took 60–72 days for seeds stored at
20℃—90% HR, and more than 146 days at 35℃—60% RH (Table 5). Seed viability
remained high for seeds stored at 20℃ or lower at low water content, being the limiting
factor to see differences between treatments the final time of storage. Clear differences
were not observed between grey and black seeds in their ageing pattern once they had lost
their dormancy. However, at the highest relative humidity tested, 90% RH, for all the
temperatures red seeds showed the lowest longevity (Table 5). On the other hand, results
also showed that low temperatures storage did not lead to secondary dormancy, remaining
germination high after 3 months storage at 5℃ (Mira et al., 2011).
結果
種子平均含水量在不同條件下測得鮮重的變化為 8.9 - 21.2% (Table 1)。在顏色沒有變異的情況下數據顯示沒有顯著的差異。在相對濕度60% 和 90%下5 和 20℃的平均含水量之間並無顯著的差異，而在35℃下差異比較顯著。
解除休眠
S. diclinis種子採收後即具有很強的休眠性，初始發芽率從6至13％（Fig. 2）。黑色種子（發芽率13％）的初始休眠率與紅色和灰色種子比較後發現無顯著的差異（發芽率分別為7和6％）(P >0.05)。
所有的溫度和相對濕度條件下發芽的時間增加了；可是，解除休眠的比率有差異。在(Fig. 2)中可以觀察到設定的兩個相對濕度，儲存在高溫下的種子失去休眠性的速度比儲存在低溫下快。在 35℃ 中儲存 40-70 天大約有 90% 發芽，其他儲存在 20℃ 140 天，和儲存在 5℃ 中 400 天後的發芽率則不到 90%。此外，種子平均最高相對濕度(60% 相對濕度， 11.53–12.59% 含水量)儲存在 20 和 35℃ 下的表現惡化，儲存期結束發芽比例減少。和預期中的一樣，種子儲存在高溫中迅速老化，20°C 140天和35°C 98天，平均濕度達 60%，開始減少發芽。由敗壞胚胎不勻稱的樣本和四唑氮鹽證實沒有發芽的種子失去活力。
線性回歸 G(概率單位) = a + b 時間(天)，種子顏色進行每個儲存條件的比較，發現截取點和斜率並沒有顯著的差異，數據是三個顏色的種子在相同的條件下。每個儲存溫度線性廻歸的結果在比較每一個相對濕度後發現斜率有顯著的差異（20和35℃，P值分別為0.004，0.000和0.0035）。因此，每個儲存條件的迴歸分析（圖3，表2），R2(係數)在0.66 和 0.91之間。利用方程式來計算克服休眠所需要的時間（發芽率100％），儲存在高溫和相對濕度中所得的值較低（表2）。儲存在相對濕度60%的比相對濕對33%的斜率值高（DRR休眠解除率，概率/天）。因此，對照圖四的不同濕度條件顯示休眠解除率與溫度無關。
解除休眠率與溫度軸線之所有斜率均為正數，解除休眠的基礎溫度(Tb) 與溫度軸線相交點為1.6 和 2.7℃，而相對濕度分別為: 33% 和 60% (Table 3).
這些解除休眠的基礎溫度值可能可以預測每個環境儲存期間積熱時間。六個群組積熱時間增加發芽的比率明顯與儲存的環境相符 (Fig. 5, Table 4)。解除休眠對積熱的反應取決於溫度和相對濕度。由(Fig. 5)解除休眠的天數和溫度可以看出相對濕度60%比33%快: 每個溫度、斜率比較有顯著差異。在接近解除休眠的基礎溫度(Tb)，5℃ 和較高的相對濕度60%，解除休眠的比率、溫度和天數也比較快，雖然研究結束後仍然有小部份的種子繼續強烈的休眠。
無休眠種子的老化
在失去最初的休眠以前立即儲存的種子;在實驗開始三種顏色的種子初始發芽的比率有96% (Table 5, Fig. 6)。排除靜止的種子，以避免計算的參數不健全
，由這些條件和顏色以Avrami 方程式計算得到的參數顯示他們失去的活力可能高於 15％。適合Avrami 方程式的條件: 20℃—90% RH; 35℃—60%, 35℃—90% RH; 而紅色種子為 5℃—90% RH。發芽率為 0％的情況下，以0.5%代替值進行計算。
溫度和相對濕度會影響種子的壽命，儲存在高溫和高相對濕度中種子會惡化得更快(Fig. 6)。(Table 5)顯示儲存在35℃—90% RH的種子只有3-8天就失去50%的活力，儲存在 20℃—90% HR的種子卻保存了60-72天，而在35℃—60% RH的種子保存得更久可長達146天。儲存在20℃或是低含水量的更低溫度中種子仍然可以保持高度的活力， 不同的處理是決定儲存時間的限制因子。老化的灰色和黑色種子樣本一旦失去了的休眠性，並沒有觀察到它們之間有明顯的差異。不過，最高相對濕度的測試結果，相對濕度90％ 顯示所有溫度紅色種子的壽命最低 (Table 5)。另一方面，研究結果還顯示，低溫儲存並不會導致二次休眠，剩餘儲存在5℃中三個月後的發芽率高。
加油!
妳可以的
就算提不起興趣
無法集中注意力
13頁長的期刊妳都可以逼自己把它看完了
真的背不起起來
到時候大不了就把稿子帶上去照唸一遍就是...
但是...
要記得妳只有15分鐘
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