Studies On Evaluation System Of Main Agronomic Character And Theis Inheritance Of Luffa[Luffa Cylindrical (L.) Roem.]

Germplasm of luffa [Luffa cylindrical L.] is the important basic of new luffa varieties breeding, genetic theory studying, and biotechnology studying and agricultural production. Although,500luffa germplasm were collected in our country, among which462were luffa [Luffa cylindrical (L.) Roem.] and about40were luffa [Luffa acutangula (Linn.) Roxb.], the studies on these germplasm were relatively less, and no normative evaluation system was constructed, therefore, affecting the tidying of germplasm, breeding of variety and introduction of new variety. The study on inheritance of main agronomic characters was relatively late and poor and unsystematic, not only restricting the utilization of excellent germplasm, but also the efficiency of breeding.In this work, on the basis of luffa germplasm that collected, the studies on main agronomic characters and its variation and their phylogenetic relationship were carried in order to establish the evaluation system of luffa germplasm. In addition, the P1, P2, F1, B1, B2and F2groups of the first female flower node and/or five characters of fruit were constructed, and the inheritance of them were studied by using the mixed major gene plus polygene-gene inheritance model, expecting promote the utilization of excellent luffa germplasm and breeding. The detailed results as follows:1. The studies on main agronomic characters and statistic analysis of luffaThe characters of102Luffa germplasm, such as growth vigor, leaf color, leaf shape, deep of leaf teeth, female/male flower color, fruit peel color, feeling of fruit surface by hand, shrinking of fruit peel, fuzz density on fruit peel, number of raised lines on fruit peel, number of concave lines on fruit peel, raised tumor density on fruit peel, raised lines color, concave lines color leaf width, leaf length, leaf stalk length, stem diameter, number of branch bine, the nodal position for first female flower bud, male flower cap diameter, female flower cap diameter, fruit length, fruit diameter, fruit index, mean fruit weight and fruit shape have been studied and analyzed. The results showed that these characters have a preliminary representative on main agronomic characteristics. In addition, These characters have been divided into different grades, frequency distribution and percentage of each grades have been investigated, reference varieties also have been given respectively.2. Correlation analysis and variation of main agronomic characters of LuffaThe correlation analysis and variation range of eleven characters of102Luffa varieties, such as male flower cap diameter, female flower cap diameter, fruit length, fruit diameter, mean fruit weight, leaf width, leaf length, leaf stalk length, stem diameter, fruit index and number of branch bine have been studied. The results showed that the coefficients of variation of fruit index and number of branch bine were large, while, the coefficients of variation of leaf width and leaf length were small. The results of correlation analysis showed that significant positive correlation were found between the fruit length and leaf stalk length; the significant negative correlation were found between the fruit length and fruit diameter, while, positive correlation between the fruit diameter and the number of branch bine; the significant positive correlation were investigated among the mean fruit weight, fruit length and fruit diameter, while, the significant positive correlation between the mean fruit weigh and leaf stalk length.3. Criterion and index of evaluation and correlation analysis of maturation traits of LuffaThe correlation between the node of the first to the third female flower bud and the first to the third male flower bud, the days of the first male and female flower of102luffa germplasm were analyzed. The results indicated that significant positive correlation was found between the node of the first to the third male flower bud, the node of the first to the third female flower bud, the node of the first to the third male flower bud and the days of the first male flower, the node of the first to the third female flower bud and the days of the first female flower, respectively. The node of the first female flower bud could be considered the standard to evaluate the maturation trait of luffa. The evaluation index as follows:less than7.6nodes of the first female flower were considered to be early maturity materials;7.7to12.9nodes were considered to be middle maturity materials and more than13.0nodes were late maturity materials.4. Characters and manifestation of the sex differentiation in Luffa The node of male and female flower bud distributed inside the30th nodes of78luffa germplasm and the distribution of asexual node, pure-male node, pure-female node and male/female node was investigated. The results indicated that the sex differentiation of luffa was complex. The asexual node always distributed under the fifth node, a little in higher node.11combinations existed in the male/female node, and the main combination was poly-male-single-female node. The male flower distributed in the pure-female node and male/female node, and there were6presentations of male flower in pure-male node. Early-maturing luffa have24.1male nodes (including pure-male node and male/female node), middle-maturing luffa have23.6male nodes, and late-maturing luffa have21.3male nodes. The results also indicated that the earlier-maturing luffa would have more number of male nodes.4manifestations of the female flower were existed in pure-female node, mainly in single female flower.23of female nodes (including pure-female node and male/female node) were in early-maturing luffa,18.7of female nodes in middle-maturing luffa, and13.5of female nodes in late-maturing luffa. The number of asexual node, pure-male node, pure-female node and male/female node were not correlated to origin of varieties, fruit shape, growth and color of leaf.5. Analysis on the phylogenetic relationship of Luffa based on ISSRPhylogenesis of43common luffa germplasm from different regions was analyzed with Inter-simple Sequence Repeat (ISSR).9primers were selected from80ISSR primers.60DNA fragments were amplified from43samples and each primer resulted in6.67DNA fragments.47fragments were polymorphic (percentage of polymorphic bands was78.3%). The value of Nei’s genetic similarity (GS) indexes of43common luffa germplasm varied from0.37to0.98, suggesting that the genetic diversity among them is short. Cluster analysis with UPGMA method showed that the43germplasm could be divided into six groups. The results according to the pedigree relations had connections with morphological traits and regions of germplasm origin.6. The inheritance of the first female flower node in LuffaInheritance of the node for first female flower in luffa(Luffa cylindrical Roem.) in P1、 P2、F1、B1、B2and F2from two crosses L1×L2(Wuyexiangsigua×Duanyuantongsigua) and L2×L3(Duanyuantongsigua×Shexingsigua) were investigated by the mixed major gene plus polygene-gene inheritance model of quantitative traits. The joint analysis results showed that the node for first female flower bud of the cross L1×L2was controlled by two adding-dominance-epistatic major gene plus adding-dominance polygene model, another cross L2×L3was controlled by one adding-dominance major gene plus adding-dominance polygene model, the third cross L3XL4was controlled by two adding major gene plus adding-dominance polygene model. Heritability values(of major gene+polygene) of the cross L1×L2of B1、B2and F2population was estimated as66.13%、51.29%and68.27%respectively; the cross L2×L3of B1、B2and F2population was estimated as82.02%、64.87%and65.62%respectively, the cross L3×L4of B1、B2and F2population was estimated as54.45%、61.88%and58.91%respectively. Environment VAR of the cross L1×L2of B1、B2and F2population was34.27%、55.40%and34.38%in total VAR respectively; while the cross L2×L3of B1、B2and F2population was34.27%、55.40%and34.38%respectively, the cross L3×L4of B1、B2and F2population was45.1%、38.02%and40.71%respectively. Conclusion:The node for first female flower bud in luffa(Luffa cylindrical Roem.) was quantitative traits and was controlled by major gene and polygene, early matured(lower node) was made by hybrid vigor impossibly, directional selection was effective on the node for first female flower bud, heritability values of the crosses was instability and environment play an important role in the inheritance.7. The inheritance of fruit characters of LuffaInheritance of the5fruit characters(fruit stalk length、fruit length、fruit diameter fruit index and mean fruit weight) for luffa(Luffa cylindrical Roem.) in P1、P2、F1、B1、B2and F2from the cross ’50-5’×’20-4’(Heiziduanyuanton) x(Guilinshuigua) were investigated by the mixed major gene plus polygene-gene inheritance model of quantitative traits. The joint analysis results showed that the fruit stalk length of the cross of’50-5’x’20-4’was controlled by two adding-dominance-epistatic major gene plus adding-dominance polygene model, the fruit length、fruit diameter、fruit index and mean fruit weight f the cross of ’50-5’×’20-4’ were controlled by two adding-dominance-epistatic major gene plus adding-dominance-epistatic polygene model. Heritability values(of major gene+polygene) of fruit stalk length in this cross of B1、B2and F2population was estimated as68.49%、70.53%and82.07%respectively; fruit length was estimated as68.85%、84.55%and81.68%respectively; fruit diameter was estimated as65.23%、73.06%and73.82%respectively; fruit index was estimated as65.23%、62.8%and78.89%respectively; and mean fruit weight was estimated as70.71%、85.35%and89.64%respectively. Environment VAR of fruit stalk length in this cross of B1. B2and F2population was31.5%.29.47%和17.92%in total VAR respectively; fruit length was31.15%、15.44%and18.32%respectively; fruit diameter was34.62%.26.94%and26.13%respectively; fruit index was34.76%.37.19%and21.11%respectively; and mean fruit weight was29.29%.14.64%and10.36%respectively. The individual selection (Genotype selection)of fruit character Of fruit stalk length on high separated generations was effective because of its small heritability values; while the mixed selection (Phenotype selection)of fruit character Of fruit length. fruit diameter, fruit index and mean fruit weight on young(low) separated generations was effective because of its big heritability values. Systematic consideration on5fruit characters was better. Environment VAR of5fruit characters has much proportion in total phenotype VAR, environment effects must be reduced to minimum in the luffa breeding research.