Landau-Ellis D, Angermüller S, Shoemaker R, Gresshoff P M
University of Tennessee, Knoxville 37901-1071.
Mol Gen Genet. 1991 Aug;228(1-2):221-6. doi: 10.1007/BF00282469.
The genetic locus (nts) controlling nitrate-tolerant nodulation, supernodulation, and diminished autoregulation of nodulation of soybean (Glycine max (L.) Merill) was mapped tightly to the pA-132 molecular marker using a restriction fragment length polymorphism (RFLP) detected by subclone pUTG-132a. The nts (nitrate-tolerant symbiotic) locus of soybean was previously detected after its inactivation by chemical mutagenesis. Mutant plant lines were characterized by abundant nodulation (supernodulation) and tolerance to the inhibitory effects of nitrate on nodule cell proliferation and nitrogen fixation. The large number of RFLPs between G. max line nts382 (homozygous for the recessive nts allele) and the more primitive soybean G. soja (PI468.397) allowed the detection of co-segregation of several diagnostic markers with the supernodulation locus in F2 families. We located the nts locus on the tentative RFLP linkage group E about 10 cM distal to pA-36 and directly next to marker pA-132. This very close linkage of the molecular marker and the nts locus may allow the application of this clone as a diagnostic probe in breeding programs as well as an entry point for the isolation of the nts gene.
利用亚克隆pUTG - 132a检测到的限制性片段长度多态性（RFLP），将控制大豆（Glycine max (L.) Merill）耐硝酸盐结瘤、超结瘤和结瘤自调控减弱的基因座（nts）紧密定位到pA - 132分子标记上。大豆的nts（耐硝酸盐共生）基因座先前是在其经化学诱变失活后被检测到的。突变植株系的特征是大量结瘤（超结瘤）以及对硝酸盐对根瘤细胞增殖和固氮的抑制作用具有耐受性。大豆品系nts382（隐性nts等位基因纯合）与更原始的大豆G. soja（PI468.397）之间存在大量RFLP，这使得在F2家系中能够检测到几个诊断性标记与超结瘤基因座的共分离。我们将nts基因座定位在暂定的RFLP连锁群E上，位于pA - 36远端约10 cM处，紧邻标记pA - 132。分子标记与nts基因座的这种紧密连锁可能使该克隆在育种计划中用作诊断探针，并作为分离nts基因的切入点。
