Have brought up the relationship indirectly many times of these interspecifics we love very much Pyrus × bretschneideri - Wikipedia
Pyrus × bretschneideri (or Pyrus bretschneideri), the ya pear or pearple or Chinese white pear  (Chinese: 白梨; pinyin: báilí), is an interspecific hybrid species of pear native to North China, where it is widely grown for its edible fruit.
Chinese white pear
Species: P. × bretschneideri
" Pyrus × bretschneideri
Chinese white pear flower
Recent molecular genetic evidence confirms some relationship to the Siberian pear (Pyrus ussuriensis), but it can also be classified as a subspecies of the Chinese pear Pyrus pyrifolia.
Along with cultivars of P. pyrifolia and P. ussuriensis, the fruit is also called the nashi pear. These very juicy, white to light yellow pears, unlike the round Nashi pears (P. pyrifolia) that are also grown in eastern Asia, are shaped more like the European pear (Pyrus communis), narrow towards the stem end. The “Ya Li” (Chinese: 鸭梨; pinyin: yālí), literally “duck pear” due to its mallard-like shape, is one cultivar widely grown in China and exported around the world. Ya pears taste similar to a mild Bosc pear, but are crisp, with a higher water content and lower sugar content."
" Breeding programs have created cultivars that are the products of further hybridizing P. ×bretschneideri with P. pyrifolia . Under the International Code of Nomenclature for algae, fungi, and plants, such backcross hybrids are named within the species P. ×bretschneideri . Cultivar ‘PremP109’, also called ‘Prem 109’, is such a hybrid, marketed under the trademark Papple ."
In this older thread The best Asian Pears i said this " The ya li pears I grafted seem like they are growing good. Anyone not familiar withYa Li should review this wiki about duck pears Pyrus × bretschneideri - Wikipedia . Nashi pears are apparently an interspecific pear hybrid pyrus × bretschneideri. These are different than the round nashi pear and are instead shaped like the tradiomal European pears."
" Tsu Li
Breeder(s): unknown; ancient.
History: Origin is lost to time. It is thought to be a P. pyrifolia X P. ussuriensis hybrid known as P. X bretschneiderii . The University of California reports that the ‘Tsu Li’ sold in North America is not the same cultivar as the ‘Tsu Li’ grown in China.
Rootstocks used: P. betulafolia (re-check)
Orchards grown in: Pittsboro, NC orchard A &.
Fruit quality: My tree died of fireblight, but it is said to be sweet, juicy and mild, subacid in flavor with a crisp texture, rather like most Asian pears.
Fruit size: large. About 240 g/fruit according to the University of California.
Fruit appearance: Attractive apple-shaped fruit with golden-yellow, mostly smooth skin and prominent lenticels.
Culinary characteristics: I never got fruit to try.
Storage characteristics: Stores for about 4 months if held at 0°C/ 32°F. I’ve not found information regarding storage in common refrigeration.
Harvest season: Unknown from first-hand experience, but mid-late September in Hickman and Davis, CA.
Bloom season: Very early; a few days *** vs Spalding. For a comparison of bloom times with other Asian pears, click here.
Pollination: Ya Li or most other early-flowering pears pollinize it well. Tsu Li makes good pollen, but will not self-pollinize.
Diseases: Susceptible to fireblight. My tree died of fireblight. Resistant to pear leafspot.
Precocity: Less precocious than most Asian pears. The University of California stated that Tsu Li typically began to fruit in its 5th year after planting on standard rootstocks, whereas the other Asian cultivars tested began to fruit in their 4th year on the same stocks. In North Carolina, my tree first fruited in its *** year on ***rootstock.
Growth habit: Very vigorous on “betch”; crotch angles wide for a pear; Dwarfing rootstock recommended, or at least P. calleryana.
References other than my own experience:
Dave Wilson Nursery
James Beutel. 1989. Asian Pears. Small Farm Center, University of California, Davis, CA.
Griggs and Iwakiri. 1977. Asian Pear Varieties in California."
Yaguang Li is a hybrid of P. ussuriensis x P. phaeocarpa which is considered pyrus bretschneideri
@tonyOmahaz5 brings up Yaguang Li and his observations
@Shuimitao brought up Yaguang Li here with explanation for @JustPeachy
With this video
More asian pear cultivars can be viewed here
Pai li is another one like ya li @tonyOmahaz5 told me about