Let X ⊆ PN be a non-degenerate projective variety of dimension d. Then the sth secant variety of X, denoted σs(X), is the Zariski closure of the union of linear spans of s-tuples of points lying on X. The study of secant varieties has a long history. The interest in this subject goes back to the Italian school at the turn of the 20th century. This topic has received renewed interest over the pa...

Genetic diversity of five improved varieties (Kaysari, Kadi, Ranger, Mesmir, Sea-River) and seven Iranian landraces (Gharayonje, Amozeynadin, Rahnani, Tazekand, Shazand, Hamedani, Yazdi) of alfalfa were assessed using Esterase (EST), Peroxidase (POX), Glutamate Oxaloacetate Transaminase (GOT) and Malate Dehydrogerase (MDH). GOT and MDH were monomorphic, whereas EST and POX showed polymorphic ba...

Larger, and deeper, root systems of new maize varieties, compared to older varieties, are thought to have enabled improved acquisition of soil resources and, consequently, greater grain yields. To compare the spatial distributions of the root systems of new and old maize varieties and their relationships with spatial variations in soil concentrations of available nitrogen (N), phosphorus (P) an...

In [8], P. Jones characterized the regular varieties of semigroups which are congruence semimodular and he partially solved the problem of characterizing the non-regular, congruence semimodular (CSM) varieties of semigroups. For regular varieties his characterization was an equational one, so necessarily a part of his argument was semigroup-theoretic. But some of his argument involved only cong...

We determine which tangential varieties of homogeneously embedded rational homogeneous varieties are spherical. We determine the homogeneous coordinate rings and rings of covariants of the tangential varieties of homogenously embedded compact Hermitian symmetric spaces (CHSS). We give bounds on the degrees of generators of the ideals of tangential varieties of CHSS and obtain more explicit info...

Identification and registration of new rice varieties are very important to be free from environmental effects and using molecular markers that are more reliable. The objectives of this study were, first, the identification and distinction of 40 rice varieties consisting of local varieties of Iran, improved varieties, and IRRI varieties using PIC, and discriminating power, second, cluster analy...

Ten commercial sugarcane varieties, N12, N14, N19, N24, N25, N26, N27, 75E247, 84E1334 and NCo376 were tested for suitability for transformation in terms of their embryogenic callus production and transient expression levels. Based on an increase in callus mass over time, varieties N12, N19, N27, NCo376 and 84E1334 outperformed other varieties on Murashige and Skoog medium containing 2,4-dichlo...