Qira'at Among Zaydi Muslims Worldwide

wa alaykum as salaam wa rahma!

Thank you for your questions!

As for the differences in qiraa'at amongst Zaydis, that would depend on the region they're in, not on the 'sub-sect' they belong to.

According to Sayyid Imam al-Qaasim b. Muhammad, upon him be peace, in his Assaas, all seven qiraa'at are acceptable, but the preferred and relied upon recitation of Ahl al-Bayt is that of Nafi' b. 'Abdur-Rahmaan, also known as the recitation of Medina. Imam al-Haadi, upon him be peace, utilised this recitation in his works, including the Ahkaam. Imam al-Haadi, upon him be peace, also viewed the 'recitation of Medina' to be the only mutawaatir recitation despite the statements of the scholars of qiraa'at to the contrary.

One can probably find those reciters who recite based upon this recitation in Yemen, but it is rare ironically. I remember an anecdote by a brother there in Yemen, who said that his grandfather used to lead the prayer and recite based upon Nafi'. After the prayer, the brothers behind him would attempt to 'correct' him and he would smile and would simply reply "Nafi'."   

As for resources one can refer to, the Sharh al-Assaas discusses this topic specifically and covers the discussions and disagreements.

Hopefully, this helps! And Allah knows best!

IRS

Thank you for your questions! Both Warsh and Qalun are relied upon. Truthfully, I have not heard either recited in Yemen; the majority recitation is Hafs. As for the other recitations in Zaydi predominate areas outside of Yemen, I have no idea. My assumption is that it is Hafs. 

And Allah knows best!

IRS

Thank you for your question! 

You may be correct about the recitation of Qalun.

As for whether the recitation of Nafi' is what the Zaydis believe to be the recitation of the Prophet, Sayyid Imam al-Murtada Muhammad b. Yahya, the son of Imam al-Haadi, upon them be peace, says explicitly in his Al-Idaah that the recitation of Medina is: "the recitation that Allah revealed to His Prophet." This is the statement of Imam al-Murtada; I don't know if any of our other imams said anything similar or contrary. 

And Allah knows best!

IRS