Mexican papita viroid: putative ancestor of crop viroids.

The potato spindle tuber disease was first observed early in the 20th century in the northeastern United States and shown, in 1971, to be incited by a viroid, potato spindle tuber viroid (PSTVd). No wild-plant PSTVd reservoirs have been identified; thus, the initial source of PSTVd infecting potatoes has remained a mystery. Several variants of a novel viroid, designated Mexican papita viroid (MPVd), have now been isolated from Solanum cardiophyllum Lindl. (papita güera, cimantli) plants growing wild in the Mexican state of Aguascalientes. MPVd's nucleotide sequence is most closely related to those of the tomato planta macho viroid (TPMVd) and PSTVd. From TPMVd, MPVd may be distinguished on the basis of biological properties, such as replication and symptom formation in certain differential hosts. Phylogenetic and ecological data indicate that MPVd and certain viroids now affecting crop plants, such as TPMVd, PSTVd, and possibly others, have a common ancestor. We hypothesize that commercial potatoes grown in the United States have become viroid-infected by chance transfer of MPVd or a similar viroid from endemically infected wild solanaceous plants imported from Mexico as germplasm, conceivably from plants known to have been introduced from Mexico to the United States late in the 19th century in efforts to identify genetic resistance to the potato late blight fungus, Phytophthora infestans.

Münşeat-i Rıfat Efendi

Each section has separate caption title.

Kitāb Tarjamat thaghr Dimyāṭ al-maḥrūs wa-mā waqaʻa bihā min ʻahd Nūḥ ʻalayhi al-salām ilá ākhir dawlat al-Turk min Kitāb al-ʻAnāṣir li-majālis al-Malik al-Nāṣir : manuscript, [1567]

A history of Damietta, Egypt.

Schedule of two thousand American historical nuggets taken : from the Stevens diggings in September 1870 and set down in chronological order of printing from 1490 to 1800 [i.e. 1776] ; described and recommended as a supplement to any printed Bibliotheca Americana /

A list of about 1400 titles not found in John Carter Brown's Bibliotheca Americana.

An ancient manuscript of the eighth or ninth century: formerly belonging to St. Mary's Abbey, or Nunnaminster, Winchester.

Mode of access: Internet.

Memorials of St. Ann's Church, Manchester, in the last century : an attempt to rectify several popular errors; to which is added a short history of church building and Sunday school work in the same town.

Mode of access: Internet.

American authors: a hand-book of American literature from early colonial to living writers,

Mode of access: Internet.

Dr. Eachard's works ... : to which are added five letters /

I. The grounds and occasions of the contempt of the clergy and religion enquired into in a letter to R.L. . - II. Observations on an answer to the Enquiry in a second letter to the same . - III. Mr. Hobbs's state of nature considered in a dialogue between Philautus and Timothy.

From Packard to Perry : a quarter century of service to the defense acquisition community /

"June 1996."

Ancient ideals : a study of intellectual and spiritual growth from early times to the establishment of Christianity /

Mode of access: Internet.