Ο μύκητας συνδέεται με τη σήψη των ριζών· οι ρίζες σαπίζουν.

συνδέεται με means is connected with, is linked to, or is associated with.

In this sentence, Ο μύκητας συνδέεται με τη σήψη των ριζών means that the fungus has a connection to root rot. In scientific or medical-style Greek, συνδέεται με is very common for saying that one thing is associated with another.

• συνδέεται = is connected / is associated
• με = with

So a very natural English rendering is The fungus is associated with root rot.

Because it is a middle/passive-form verb.

The base verb is συνδέω = I connect.
But συνδέεται is the 3rd person singular present middle/passive form, literally something like is connected.

This is very common in Greek: a verb with passive endings can have a meaning that sounds more natural in English as:

• passive: is connected
• or sometimes almost active/intransitive: is associated

So here:

• συνδέει = it connects
• συνδέεται = it is connected / it is associated

This is about the final -ν in the feminine article.

The full accusative singular feminine article is την, but in Modern Greek the final -ν is often dropped before certain consonants. Since σήψη begins with σ, it is very normal to write:

• τη σήψη

instead of:

• την σήψη

Both forms may be understood, but τη σήψη is the normal standard form here.

Also, με takes the accusative, so σήψη appears with the accusative article:

• με τη σήψη = with the rot / with the decay

των ριζών is genitive plural, and it means of the roots.

So:

• η ρίζα = the root
• οι ρίζες = the roots
• των ριζών = of the roots

In τη σήψη των ριζών, Greek is literally saying:

• the rot of the roots

This is very natural Greek. English often prefers a compound noun like root rot, but Greek commonly uses a noun + genitive structure.

They are related in meaning, but they are different parts of speech.

• σήψη = rot, decay, rotting — a noun
• σαπίζουν = they rot / they are rotting — a verb

So the sentence gives the idea twice in two different ways:

1. Ο μύκητας συνδέεται με τη σήψη των ριζών
   = The fungus is associated with the rot/rotting of the roots.

2. οι ρίζες σαπίζουν
   = The roots rot / are rotting.

This kind of repetition is common and can make the meaning clearer.

Because σαπίζω can work as an intransitive active verb in Modern Greek.

So:

• οι ρίζες σαπίζουν = the roots rot

Greek does not need a passive form here, just as English does not need one in the roots rot.

Compare:

• σαπίζω κάτι = I rot something / I cause something to rot
• κάτι σαπίζει = something rots

So σαπίζουν is exactly the right form for the roots rot.

Greek uses the definite article a lot, and the form changes for gender, number, and case.

In this sentence:

• ο μύκητας = the fungus
  masculine singular nominative

• τη σήψη = the rot / the decay
  feminine singular accusative

• των ριζών = of the roots
  plural genitive

• οι ρίζες = the roots
  feminine plural nominative

English has just one main definite article, the. Greek has many forms, and choosing the right one is an important part of the grammar.

Because they are different cases.

• οι ρίζες = nominative plural, used when roots are the subject
  Example: οι ρίζες σαπίζουν = the roots rot

• των ριζών = genitive plural, used for of the roots
  Example: η σήψη των ριζών = the rot of the roots

So the noun changes form depending on its role in the sentence.

The symbol · is called the ano teleia in Greek.

It works like a strong pause, often similar to an English:

• semicolon ;
• or sometimes a colon :

In this sentence, it separates two closely related statements:

• Ο μύκητας συνδέεται με τη σήψη των ριζών
• οι ρίζες σαπίζουν

So you can read it as something like:

The fungus is associated with root rot; the roots rot.

σαπίζουν is the 3rd person plural present active form of σαπίζω.

That means:

• σαπίζω = I rot / I am rotting
• σαπίζεις = you rot
• σαπίζει = it rots
• σαπίζουμε = we rot
• σαπίζετε = you (plural) rot
• σαπίζουν = they rot

Since οι ρίζες is plural, the verb must also be plural:

• οι ρίζες σαπίζουν = the roots rot

Grammatically, Ο μύκητας means the fungus in the singular.

In context, it can mean either:

• a specific fungus already known from the discussion, or
• a fungus being discussed as a type in a scientific statement

Greek often uses the singular with the article in general descriptions, especially in formal or scientific language.

So depending on context, English might translate it as:

• The fungus
• or sometimes more generally This fungus / The fungus in question

The Greek itself is completely natural.