Pistillate flower abscission of walnut genotypes.

摘要

In walnut cultivars and genotypes, there is a kind of abnormal pistillate flower abscission (PFA) that is different from the abscission of non-pollinated flowers. One of the causes of this disorder is reported as high pollen load during pollination. This study was conducted during 1997-98 in Iran, to determine the PFA susceptibility of 60 walnut genotypes in 20 half-sib (hs) families. The evaluation of flower number before and after abscission together with branch diameter and fruit number was done on three branches in each genotype. There were great differences between different hs families and genotypes. The maximum and minimum abscission (two year means) were belong to families: k66 and k22 with 24% and 76% respectively. Meanwhile the least and highest abscission on genotypes were 11% and 92% in k66/2 and k22/2. There were also significant differences on flower density (number of flowers/branch cross sectional area cm2). The families K104 and K39, with 4.55 and 0.56, and the genotypes K104/2 and K13/3, with 6.6 and 0.27, showed the maximum and minimum of FD, respectively. Narrow sense heritability of PFA and FD 0.55 and 0.34 were estimated, respectively..