🌱 种子萌发：破土的第一步🌱 Seed Germination: the First Break Through
上一片里，花完成了传粉，谢幕后把种子留给了大地。种子落进土里，条件一齐就醒过来——可它是按什么顺序“开工”的？这片带你逐天看一遍。Last leaf, the flower finished pollination and left seeds to the earth. Once conditions line up, a seed wakes up — but in what order does it get to work? This leaf walks you through, day by day.
第 1 步：七天的观察日记Step 1: A seven-day observation diary
把一粒种子埋进土里，接下来七天它会干什么？Bury a seed — what does it do over the next seven days?
顺序是固定的：第 1 天先喝水，种子吸水膨胀、种皮撑亮；第 3 天白白的胚根从裂缝钻出来向下扎；第 5 天弯着钩的胚芽顶出土面；第 7 天子叶张开、变绿开工。一句话：先喝水，再扎根，后出苗。The order never changes: Day 1, the seed drinks and swells, its coat shining tight; Day 3, a white root pokes from the crack and digs down; Day 5, the hooked shoot breaks the surface; Day 7, the seed leaves open and turn green to work. In short: drink first, root down, then sprout up.
奇怪，为什么急着先长根，不先出芽去晒太阳？Odd — why rush the root instead of a sunbathing shoot?
第 2 步：根为什么打头阵Step 2: Why the root goes first
因为根是“生命线”：扎稳了才站得住，够得着水。先出芽的小苗东倒西歪，土一干就渴死。而且出土前幼芽见不到光，没法光合作用——它吃什么？吃“随身干粮”：子叶里存好的营养。等叶子张开变绿，才改吃“自己做的新饭”。Because the root is the lifeline: anchored, it can stand and reach water. A shoot-first seedling wobbles over and dries out. And before breaking the surface it sees no light, so photosynthesis is off — what does it eat? Its packed lunch: the food stored in the seed leaves. Only when leaves open and turn green does it switch to home-cooked meals.
懂了顺序，种地的老把式是怎么用的？Now that we know the order — how do farmers put it to use?
第 3 步：播种的门道Step 3: The craft of sowing
埋的深度有讲究：约两粒种子叠起来高最合适。太深，芽在黑暗里耗尽干粮也够不着空气；太浅，一晒就干。播前农民还会做“发芽率测试”：抓一把种子催芽，看多少颗能发芽——发芽率高，才敢按量下种，苗才出得齐。Depth matters: about two seed-widths is ideal. Too deep, the sprout burns its lunch in the dark before reaching air; too shallow, one sunny day dries it out. Before sowing, farmers run a germination test: sprout a handful of seeds and count how many wake up. A high germination rate tells them how much seed to sow — and promises an even stand of seedlings.
🎮 萌发观察日记（30 秒）🎮 Your turn: the germination diary (30 seconds)
先在观察台逐天点看种子的七天变化，再用 4 关考考你：两关排顺序、两关找异常。Tap through seven days on the observation deck, then take 4 quiz levels: two to put in order, two to spot the odd one.
一句话记住它：萌发 = 先喝水、根先出、芽出土、子叶供饭——顺序不能乱。Remember it in one line: germination = drink first, root first, shoot out, seed leaves catering — the order never shuffles.
顺序铁律：吸水膨胀 → 胚根钻出 → 胚芽出土 → 子叶张开变绿The iron order: swell with water → root pokes out → shoot breaks soil → seed leaves open green根先出：站稳又够水；出土前靠子叶里的“随身干粮”Root first: to stand and to drink; before emerging, live on the seed leaves' packed lunch播种约两粒种子深；播前测发芽率，苗才出得齐Sow about two seed-widths deep; test germination rate first for an even stand
内容参考 OpenStax 等公开教材，多来源核对 · AI 生成、人工审核 · 发现错误欢迎指正，帮这片叶子长得更好。Based on OpenStax and other open textbooks, cross-checked across sources · AI-generated, human-reviewed · Spotted a mistake? Tell us — help this leaf grow.
Back to tree
