I've just finished writing a list of 190 items. I'd like to make some links of the list dofollow, but I don't know if Google still allows dofollow links and how many per article.
I have read your question several times and am confused.
Make links. If you do not trust who you are linking to, do not make a link or at least make it nofollow. Use nofollow if you do not know if you trust who you are linking to out of safety. If you trust who you are linking to then the links should be follow. Generally, it is that simple. Link to quality sites only if you are making links manually. If they are automated, then they should be nofollow.
For internal links, then the decision becomes simpler. If you want search engines to follow the link then it should be follow. If not, then nofollow. Simple.
Google is not the boss and does not run the Internet. Google has to follow the rules just like the rest of us. This means that as long as you follow the rules of the road and do not try and abuse the search engines, all should be fine.
and I'd like to make some links of the list dofollow.
That's the default for links, and to achieve that, you can have a code fragment like this:
<p>Here's the list</p> <ul> <li><a href="www.example.com/followme">Item 1</a></li> <li><a href="www.example.com/followthis">Item 2</a></li> <li><a href="www.example.com/followthis">Item 190</a></li> </ul>
Now if you want a link to not be followed, then you need to add
rel=nofollow. Here's a code listing samples of links that search engines will not crawl:
<p>Here's the bad list</p> <ul> <li><a href="www.example.com/terriblesite" rel="nofollow">Item 122</a></li> <li><a href="www.example.com/horrible" rel="nofollow">Item 12</a></li> <li><a href="www.example.com/baaaaaad" rel="nofollow">Item 160</a></li> </ul>
Google will not attempt to consider the links for indexing that are marked as nofollow unless an external site makes reference to them.
Here's googles info on nofollow: https://support.google.com/webmasters/answer/96569?hl=en
but I don't know if Google still allows dofollow backlinks and how many per article.
You will have a backlink if an external website has an active link to your site. For example:
If your site is example.com and the external site is exampleexternal.com, and exampleextenal.com has the following code fragment that is currently processed by a user's browser:
<p>Here's info on how to run robots. <a href="http://example.com/running-robots">Click here to find out</a></p>
then you have a backlink. If you're trying to control the follow/nofollow status of such links, you'll have a very hard time doing so because if your site is extremely popular, you may have several backlinks (example: your url could be listed on 50,000 other sites).
Additionally, asking people that link to your site to not follow it (via rel="nofollow") is bad since valuable "link juice" will not be passed on to your site and therefore you might not rank high in search engines.
If on the other hand, your site is the worst in the world to the point where all people will see are pop-ups on each page with no valuable content then by all means, ask all the people linking to your site to label the links to your site as nofollow.
I did ramble on a-lot, but please see https://support.google.com/webmasters/answer/96569?hl=en and watch google's videos so you understand what backlinks and "nofollow" are.