bp_blast2tree: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/bp_blast2tree - from package: bioperl

You may install the required package with command apt-get install {package}

Error in other languages:
bp_blast2tree: bevel nie gevind nie
bp_blast2tree: comandă negăsită
bp_blast2tree: comando não encontrado
bp_blast2tree: commande introuvable
bp_blast2tree: command not found
bp_blast2tree: käsku ei ole
bp_blast2tree: không tìm thấy lệnh
bp_blast2tree: komanda nerasta
bp_blast2tree: Kommando nicht gefunden.
bp_blast2tree: kommandot finns inte
bp_blast2tree: komut yok
bp_blast2tree: nie znaleziono polecenia
bp_blast2tree: níor aimsíodh an t-ordú
bp_blast2tree: no se encontró la orden
bp_blast2tree: no s'ha trobat l'ordre
bp_blast2tree: opdracht niet gevonden
bp_blast2tree: parancs nem található
bp_blast2tree: perintah tidak ditemukan
bp_blast2tree: príkaz nenájdený
bp_blast2tree: příkaz nenalezen
bp_blast2tree: команда не найдена
bp_blast2tree: командата не е открита
bp_blast2tree: 命令找不到
bp_blast2tree: コマンドが見つかりません