Inheritance of flowering, maturity, fruit yield, and winter hardiness of sea buckthorn (Hippophae rhamnoides)

Eight characters relating to flowering and maturity, berry yield, and winte r hardiness were estimated on the basis of intersubspecific or interprovena nce hybrids to determine heterosis, heritability, and genetic and phenotypi c correlations in sea buckthorn (Hippophae rhamnoides L.). Two provenances of ssp. rhamnoides, one of Finnish (Fin) and one of Danish (Dan) origin, we re dominant to ssp. sinensis and Russian derived provenances (ssp. turkesta nica) for most characters related to flowering or maturity. This tendency f or dominance or overdominance also extended to berry yield and winter hardi ness, except for hybrids between Finnish origins and Siberian (ssp. mongoli ca) origins. The start of maturity (Ms) and half maturity (Mh) showed the h ighest heritabilities (h(2) = 0.88 and 0.81, respectively). The hybrids wer e matroclinal, suggesting that Ms and Mh may be sex-linked or cytoplasmical ly inherited characters. Winter hardiness was the trait with the lowest her itability (h(2) = 0.02), suggesting that the climate at the testing site wa s not severe enough to differentiate variation among half sibs or full sibs derived from Fin x Dan, which on average proved hardier than the native pa rental provenance Fin. Full maturity (Mf) showed a moderate heritability bu t was stable across 2 years (r(a) = 1). High genetic correlations among Mf, Ms, and Mh (r(G) = 0.94, 0.96, and 1.00, respectively) suggest that these characters were controlled by the same genes. Yield showed a negative genet ic correlation with all characters pertaining to flowering and maturity, in dicating that selection for early flowering or early maturity should result in a gain in yield.