Analysis In Genetic Diversity For F₁Population Of Erianthus Rockii

Developing new type of parental materials plays significant role in sugarcane breeding. In this process, a mass ofoffspring generated from initial crossing is the first confusing the selection for elite clones as parents in future cross plan.The genetic diversity of offspring population will be very useful for selecting clones and back crossing. Morphologicaland SSR markers were used for analyzing the genetic diversity on offspring which were from family Ludashi×Yunnan95-19in this study, and genetic characters, relationship and diversity of them will be presented in this report, wehope these researches can provide suggestion for sugarcane breeders on how to utilize Erianthusrockii and itsoffspring clones. The results indicated that:1.Sixty-two offspring in combination Ludashi×Yunnan95-19were identified by SSR molecular markers and allof them are true hybrids.2. Genomes DNA of62offspring were used as template; ten pairs of polymorphic primers were used to PCRamplification,81amplified fragments were gained,81.55%of which were of polymorphism by average. Thepolymorphism bands detected from each pair of primers were6on average, which indicated abundant genetic diversityamong62offspring.3.Genetic similarity(GS) among62offspring were determined by data from SSR marker, The GS was rangedfrom0.4074to0.9383with mean value of0.6519, which indicated high similarity among individuals. The clusteranalysis based on GS divided62individuals into3groups at GS value0.672.4. The genetic differentiation of main phenotypic traits was found among62offspring, and there were abundantgenetic diversity and high genetic variation among the population. The traits like millable stalks, single stalk weight andlength of internodes contributed largely to genetic dissimilarity for quantitative traits, whereas there were lower geneticvariation in plant height, stalk diameter and brix. With regarding to qualitative traits, there were much higher geneticdiversity in traits hair on leaf sheath, shape of internal/external auricle, color of unexposed internodes, seedling vigor;on the other hand, there was no genetic differentiation for six traits root pintrangement, shape of stem, shape ofinternodes, buds location, leaf posture and internodes cracks.5. The offspring were divided into4groups by using cluster analyzing from28phenotypic traits. The second groupwas the largest one which consisted of53individuals, and showed the highest similarity to group1. Group3and4wasconsisted of1and2clones, respectively. Group4was differed with others and was unique so far as geneticrelationships was concerned.